National Trends in Sulfur_Dioxide Concentrations in 1990 - 2008
Year Mean Number of Trend Sites 10th Percentile 90th Percentile
1990 0.00802631578947 266 0.0019 0.0145
1991 0.00785187969924 266 0.0018 0.0144
1992 0.00728489974937 266 0.00183333333333 0.0131
1993 0.00719630325814 266 0.0019 0.0127
1994 0.00693327067669 266 0.0019 0.0126
1995 0.0055227443609 266 0.0016 0.0104
1996 0.00550375939849 266 0.0016 0.01
1997 0.00542105263157 266 0.0016 0.0096
1998 0.00528458646616 266 0.0017 0.0096
1999 0.00512844611528 266 0.0018 0.0091
2000 0.00491140350877 266 0.0017 0.0087
2001 0.00460563909774 266 0.0016 0.0082
2002 0.00435789473684 266 0.0015 0.0081
2003 0.00434586466165 266 0.0015 0.0083
2004 0.00413095238095 266 0.0015 0.0074
2005 0.00421127819548 266 0.0016 0.0074
2006 0.00370284461152 266 0.0013 0.0069
2007 0.00356860902255 266 0.0013 0.0064
2008 0.00325612781954 266 0.0012 0.0062