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Statistical data set

Figure 15: Mean hours when O3 pollution was 鈥楳oderate鈥� or higher for urban background sites, 1992 to 2024

Updated 26 June 2025

锘縎ite type Year Daily Air Quality Index Mean number of hours per site Number of sites
Urban Background 1992 Moderate 4 12 4
Urban Background 1993 Moderate 4 10.5 8
Urban Background 1994 Moderate 4 21.38461538 13
Urban Background 1995 Moderate 4 53.75 12
Urban Background 1996 Moderate 4 38.5 18
Urban Background 1997 Moderate 4 35.12903226 31
Urban Background 1998 Moderate 4 19.80952381 42
Urban Background 1999 Moderate 4 61.47619048 42
Urban Background 2000 Moderate 4 29.48780488 41
Urban Background 2001 Moderate 4 40.13953488 43
Urban Background 2002 Moderate 4 27.73333333 45
Urban Background 2003 Moderate 4 104.5744681 47
Urban Background 2004 Moderate 4 44.68 50
Urban Background 2005 Moderate 4 38.14285714 49
Urban Background 2006 Moderate 4 102.7708333 48
Urban Background 2007 Moderate 4 48.26666667 45
Urban Background 2008 Moderate 4 96.11627907 43
Urban Background 2009 Moderate 4 34.31707317 41
Urban Background 2010 Moderate 4 19.5 42
Urban Background 2011 Moderate 4 49.11627907 43
Urban Background 2012 Moderate 4 35.19047619 42
Urban Background 2013 Moderate 4 40.46341463 41
Urban Background 2014 Moderate 4 32.78571429 42
Urban Background 2015 Moderate 4 22.64285714 42
Urban Background 2016 Moderate 4 39.34146341 41
Urban Background 2017 Moderate 4 21.02439024 41
Urban Background 2018 Moderate 4 93.38095238 42
Urban Background 2019 Moderate 4 48.15384615 39
Urban Background 2020 Moderate 4 93.74358974 39
Urban Background 2021 Moderate 4 33.81578947 38
Urban Background 2022 Moderate 4 74.1 40
Urban Background 2023 Moderate 4 77.94117647 51
Urban Background 2024 Moderate 4 49.11666667 60
Urban Background 1992 Moderate 5 1 4
Urban Background 1993 Moderate 5 3.625 8
Urban Background 1994 Moderate 5 7.923076923 13
Urban Background 1995 Moderate 5 31.16666667 12
Urban Background 1996 Moderate 5 19.61111111 18
Urban Background 1997 Moderate 5 10.5483871 31
Urban Background 1998 Moderate 5 2.714285714 42
Urban Background 1999 Moderate 5 21.38095238 42
Urban Background 2000 Moderate 5 7.536585366 41
Urban Background 2001 Moderate 5 14.81395349 43
Urban Background 2002 Moderate 5 4.933333333 45
Urban Background 2003 Moderate 5 42.87234043 47
Urban Background 2004 Moderate 5 13.42 50
Urban Background 2005 Moderate 5 10 49
Urban Background 2006 Moderate 5 50.08333333 48
Urban Background 2007 Moderate 5 6.488888889 45
Urban Background 2008 Moderate 5 22.95348837 43
Urban Background 2009 Moderate 5 3.829268293 41
Urban Background 2010 Moderate 5 3.904761905 42
Urban Background 2011 Moderate 5 8.093023256 43
Urban Background 2012 Moderate 5 8.428571429 42
Urban Background 2013 Moderate 5 5.804878049 41
Urban Background 2014 Moderate 5 2.571428571 42
Urban Background 2015 Moderate 5 5 42
Urban Background 2016 Moderate 5 7.146341463 41
Urban Background 2017 Moderate 5 5.048780488 41
Urban Background 2018 Moderate 5 20.88095238 42
Urban Background 2019 Moderate 5 22.87179487 39
Urban Background 2020 Moderate 5 27.48717949 39
Urban Background 2021 Moderate 5 6.236842105 38
Urban Background 2022 Moderate 5 27.725 40
Urban Background 2023 Moderate 5 29.64705882 51
Urban Background 2024 Moderate 5 8.833333333 60
Urban Background 1992 Moderate 6 0 4
Urban Background 1993 Moderate 6 2.625 8
Urban Background 1994 Moderate 6 3.461538462 13
Urban Background 1995 Moderate 6 12.58333333 12
Urban Background 1996 Moderate 6 8.555555556 18
Urban Background 1997 Moderate 6 3.903225806 31
Urban Background 1998 Moderate 6 0.380952381 42
Urban Background 1999 Moderate 6 8.047619048 42
Urban Background 2000 Moderate 6 1.12195122 41
Urban Background 2001 Moderate 6 4.069767442 43
Urban Background 2002 Moderate 6 0.866666667 45
Urban Background 2003 Moderate 6 18.5106383 47
Urban Background 2004 Moderate 6 2.7 50
Urban Background 2005 Moderate 6 2.387755102 49
Urban Background 2006 Moderate 6 24.29166667 48
Urban Background 2007 Moderate 6 0.444444444 45
Urban Background 2008 Moderate 6 3.255813953 43
Urban Background 2009 Moderate 6 1.487804878 41
Urban Background 2010 Moderate 6 0.547619048 42
Urban Background 2011 Moderate 6 0.953488372 43
Urban Background 2012 Moderate 6 1.476190476 42
Urban Background 2013 Moderate 6 1.609756098 41
Urban Background 2014 Moderate 6 0.071428571 42
Urban Background 2015 Moderate 6 1.714285714 42
Urban Background 2016 Moderate 6 0.390243902 41
Urban Background 2017 Moderate 6 1.024390244 41
Urban Background 2018 Moderate 6 3.928571429 42
Urban Background 2019 Moderate 6 6.256410256 39
Urban Background 2020 Moderate 6 11.17948718 39
Urban Background 2021 Moderate 6 0.263157895 38
Urban Background 2022 Moderate 6 10.15 40
Urban Background 2023 Moderate 6 7.039215686 51
Urban Background 2024 Moderate 6 1.116666667 60
Urban Background 1992 High 7 0 4
Urban Background 1993 High 7 0.125 8
Urban Background 1994 High 7 1.461538462 13
Urban Background 1995 High 7 4.416666667 12
Urban Background 1996 High 7 1.666666667 18
Urban Background 1997 High 7 1.806451613 31
Urban Background 1998 High 7 0.142857143 42
Urban Background 1999 High 7 2.380952381 42
Urban Background 2000 High 7 0.097560976 41
Urban Background 2001 High 7 1.139534884 43
Urban Background 2002 High 7 0.311111111 45
Urban Background 2003 High 7 6.319148936 47
Urban Background 2004 High 7 0.52 50
Urban Background 2005 High 7 0.551020408 49
Urban Background 2006 High 7 10.1875 48
Urban Background 2007 High 7 0 45
Urban Background 2008 High 7 0.186046512 43
Urban Background 2009 High 7 0.219512195 41
Urban Background 2010 High 7 0 42
Urban Background 2011 High 7 0 43
Urban Background 2012 High 7 0.047619048 42
Urban Background 2013 High 7 0.024390244 41
Urban Background 2014 High 7 0 42
Urban Background 2015 High 7 0.428571429 42
Urban Background 2016 High 7 0 41
Urban Background 2017 High 7 0.219512195 41
Urban Background 2018 High 7 0.619047619 42
Urban Background 2019 High 7 1.58974359 39
Urban Background 2020 High 7 1.974358974 39
Urban Background 2021 High 7 0 38
Urban Background 2022 High 7 1.45 40
Urban Background 2023 High 7 0.882352941 51
Urban Background 2024 High 7 0 60
Urban Background 1992 High 8 0 4
Urban Background 1993 High 8 0 8
Urban Background 1994 High 8 0 13
Urban Background 1995 High 8 0.25 12
Urban Background 1996 High 8 0.111111111 18
Urban Background 1997 High 8 0.225806452 31
Urban Background 1998 High 8 0 42
Urban Background 1999 High 8 0.285714286 42
Urban Background 2000 High 8 0 41
Urban Background 2001 High 8 0.093023256 43
Urban Background 2002 High 8 0 45
Urban Background 2003 High 8 0.765957447 47
Urban Background 2004 High 8 0 50
Urban Background 2005 High 8 0 49
Urban Background 2006 High 8 1.604166667 48
Urban Background 2007 High 8 0 45
Urban Background 2008 High 8 0 43
Urban Background 2009 High 8 0 41
Urban Background 2010 High 8 0 42
Urban Background 2011 High 8 0 43
Urban Background 2012 High 8 0 42
Urban Background 2013 High 8 0 41
Urban Background 2014 High 8 0 42
Urban Background 2015 High 8 0 42
Urban Background 2016 High 8 0 41
Urban Background 2017 High 8 0 41
Urban Background 2018 High 8 0 42
Urban Background 2019 High 8 0.076923077 39
Urban Background 2020 High 8 0 39
Urban Background 2021 High 8 0 38
Urban Background 2022 High 8 0 40
Urban Background 2023 High 8 0 51
Urban Background 2024 High 8 0 60
Urban Background 1992 High 9 0 4
Urban Background 1993 High 9 0 8
Urban Background 1994 High 9 0 13
Urban Background 1995 High 9 0 12
Urban Background 1996 High 9 0 18
Urban Background 1997 High 9 0 31
Urban Background 1998 High 9 0 42
Urban Background 1999 High 9 0.095238095 42
Urban Background 2000 High 9 0 41
Urban Background 2001 High 9 0 43
Urban Background 2002 High 9 0 45
Urban Background 2003 High 9 0 47
Urban Background 2004 High 9 0 50
Urban Background 2005 High 9 0 49
Urban Background 2006 High 9 0.125 48
Urban Background 2007 High 9 0 45
Urban Background 2008 High 9 0 43
Urban Background 2009 High 9 0 41
Urban Background 2010 High 9 0 42
Urban Background 2011 High 9 0 43
Urban Background 2012 High 9 0 42
Urban Background 2013 High 9 0 41
Urban Background 2014 High 9 0 42
Urban Background 2015 High 9 0 42
Urban Background 2016 High 9 0 41
Urban Background 2017 High 9 0 41
Urban Background 2018 High 9 0 42
Urban Background 2019 High 9 0 39
Urban Background 2020 High 9 0 39
Urban Background 2021 High 9 0 38
Urban Background 2022 High 9 0 40
Urban Background 2023 High 9 0 51
Urban Background 2024 High 9 0 60
Urban Background 1992 Very High 10 0 4
Urban Background 1993 Very High 10 0 8
Urban Background 1994 Very High 10 0 13
Urban Background 1995 Very High 10 0 12
Urban Background 1996 Very High 10 0 18
Urban Background 1997 Very High 10 0 31
Urban Background 1998 Very High 10 0 42
Urban Background 1999 Very High 10 0 42
Urban Background 2000 Very High 10 0 41
Urban Background 2001 Very High 10 0 43
Urban Background 2002 Very High 10 0 45
Urban Background 2003 Very High 10 0 47
Urban Background 2004 Very High 10 0 50
Urban Background 2005 Very High 10 0 49
Urban Background 2006 Very High 10 0 48
Urban Background 2007 Very High 10 0 45
Urban Background 2008 Very High 10 0 43
Urban Background 2009 Very High 10 0 41
Urban Background 2010 Very High 10 0 42
Urban Background 2011 Very High 10 0 43
Urban Background 2012 Very High 10 0 42
Urban Background 2013 Very High 10 0 41
Urban Background 2014 Very High 10 0 42
Urban Background 2015 Very High 10 0 42
Urban Background 2016 Very High 10 0 41
Urban Background 2017 Very High 10 0 41
Urban Background 2018 Very High 10 0 42
Urban Background 2019 Very High 10 0 39
Urban Background 2020 Very High 10 0 39
Urban Background 2021 Very High 10 0 38
Urban Background 2022 Very High 10 0 40
Urban Background 2023 Very High 10 0 51
Urban Background 2024 Very High 10 0 60