Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg.,
1990,3913,5601,5082,5060,5272,5423,5260,5418,5054,5091,4960,4662,5061,
1991,4607,4929,5198,5440,5414,5522,5421,5615,5222,5742,5607,5461,5350,
1992,5358,5902,6178,6378,6312,6574,6488,6263,6300,6186,5896,5524,6129,
1993,4818,5607,5965,6467,6479,6463,6372,6364,6298,6458,6193,6343,6154,
1994,5962,6230,6716,6936,7249,7231,7058,7332,7058,7318,6728,6891,6897,
1995,,6347,6596,6850,6872,7173,6992,7235,6469,7472,6755,6440,,
1996,6291,6818,6921,6663,7519,8091,7765,7978,8495,8017,7736,6917,7434,
1997,6920,7389,7812,8227,8375,8404,7820,7667,7516,7976,7280,7110,7708,
1998,6801,7384,7676,8036,7904,8177,7956,8214,8052,7983,7478,7561,7769,
1999,7367,7427,7930,8469,8566,8829,8453,8656,8575,8491,8078,7811,8221,
2000,7712,8369,8216,8824,9163,9139,9189,9951,10183,9394,8629,8418,8932,
2001,7950,8390,9118,9653,9841,8994,9886,9623,9318,9092,8778,8306,9079,
2002,8694,9177,9687,10338,10386,10271,11535,12945,11906,,,,,