National Trends in Sulfur_Dioxide Concentrations in 2000 - 2010
Year Mean Number of Trend Sites 10th Percentile 90th Percentile
2000 4.62315731274597 341 0.98347210140425 8.90234302862419
2001 4.39156645591101 341 0.81023479831426 8.79845050878816
2002 4.04196271350825 341 0.71987534626038 8.19703215169002
2003 4.01351473551143 341 0.88780185758513 8.15094555873926
2004 3.83268107550168 341 0.82708236927348 7.26256077795786
2005 3.88739090296853 341 0.71319972356599 7.48055623923209
2006 3.41420511803003 341 0.62422997946611 6.90059433632444
2007 3.26354209502935 341 0.66107871720116 6.44809004909592
2008 2.91597081338309 341 0.56641981022911 6.14167830392281
2009 2.37965318680763 341 0.49885500783415 5.22512849800114
2010 2.23471228226568 341 0.44275161588181 4.65326163198504