National Trends in Nitrogen_Dioxide Concentrations in 1980 - 2008
Year Mean Number of Trend Sites 10th Percentile 90th Percentile
1980 0.02818133333333 75 0.0145 0.0498
1981 0.02773644444444 75 0.0136 0.0498
1982 0.02670288888888 75 0.0136 0.0476
1983 0.025912 75 0.0126 0.0456
1984 0.02653244444444 75 0.014 0.0463
1985 0.026328 75 0.0139 0.0475
1986 0.026398 75 0.0145 0.0468
1987 0.02595555555555 75 0.0149 0.0426
1988 0.026526 75 0.0154 0.0472
1989 0.02574266666666 75 0.0136 0.0428
1990 0.02446577777777 75 0.0129 0.0408
1991 0.02433088888888 75 0.0113 0.0426
1992 0.02336666666666 75 0.0128 0.0396
1993 0.022788 75 0.0126 0.0372
1994 0.024036 75 0.0127 0.0415
1995 0.02298986666666 75 0.01265 0.0393
1996 0.022454 75 0.0122 0.0376
1997 0.021516 75 0.0119 0.0338
1998 0.02143266666666 75 0.0115 0.0355
1999 0.02209933333333 75 0.0124 0.0376
2000 0.020594 75 0.0114 0.0361
2001 0.02051733333333 75 0.0116 0.0356
2002 0.01962666666666 75 0.0116 0.0329
2003 0.01898933333333 75 0.0107 0.0312
2004 0.01751533333333 75 0.0105 0.0272
2005 0.01737466666666 75 0.0092 0.0274
2006 0.01632 75 0.0097 0.027
2007 0.01575466666666 75 0.0095 0.0255
2008 0.01484266666666 75 0.0082 0.0234