YEAR,Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec,Annual 24-hr Avg.
1998,6375,6920,7004,7557,7169,6341,7185,,8033,7336,6653,6429
1999,6435,6541,7599,8099,8337,,8134,8188,,8195,7760,7087
2000,7070,8307
2001, ,,,,,8550,7277
2002,
2003,,7727,8212,8518,,,,6700,6644,6454,5554,5535
2004,5440,5839,6425,6694,,,6613,6648,6683,6278,5961,5798
2005,
2006,
2007,
2008,