year,Pb (3-month),CO (8-hour),NO2 (annual),NO2 (1-hour),O3 (8-hour),PM2.5 (annual),PM2.5 (24-hour),PM10 (24-hour),SO2 (1-hour)
1990,,-36,-63,-24,25,,,-43,71
1991,,-34,-63,-25,26,,,-43,62
1992,,-41,-64,-30,20,,,-51,59
1993,,-45,-65,-32,21,,,-51,47
1994,,-42,-63,-31,22,,,-52,46
1995,,-47,-64,-32,28,,,-51,21
1996,,-52,-65,-36,22,,,-57,12
1997,,-56,-67,-38,21,,,-56,15
1998,,-57,-67,-40,28,,,-58,15
1999,,-58,-66,-37,25,,,-56,17
2000,,-61,-68,-40,17,12,0,-57,7
2001,,-65,-68,-42,19,10,1,-58,3
2002,,-68,-69,-45,25,7,-2,-59,-4
2003,,-70,-70,-44,17,3,-10,-56,-4
2004,,-72,-73,-49,7,0,-8,-63,-5
2005,,-76,-73,-50,14,7,-2,-61,-2
2006,,-76,-74,-50,12,-3,-15,-61,-7
2007,,-79,-75,-51,12,-1,-10,-58,-13
2008,,-80,-77,-52,7,-9,-21,-62,-23
2009,,-80,-79,-56,-1,-18,-28,-66,-32
2010,51,-82,-79,-56,4,-17,-28,-67,-37
2011,52,-83,-80,-57,5,-18,-29,-63,-47
2012,34,-83,-81,-59,7,-23,-37,-64,-50
2013,-8,-84,-81,-59,-4,-25,-34,-62,-56
2014,-48,-83,-82,-58,-4,-26,-36,-63,-58
2015,-70,-84,-83,-61,-2,-29,-37,-63,-65
2016,-69,-84,-84,-62,-2,-35,-45,-65,-76
2017,-68,-85,-84,-62,-3,-33,-40,-62,-80
2018,-72,-83,-84,-62,-1,-31,-34,-56,-80
2019,-78,-86,-85,-64,-7,-36,-45,-69,-83
2020,-79,-83,-86,-65,-6,-33,-30,-58,-85