Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg.,
1990,3470,3921,5893,6304,5479,7296,8166,6827,5769,4969,4284,3898,5532,
1991,3547,5305,5829,6180,6926,8353,8103,7724,6456,6227,4831,4318,6153,
1992,4327,4562,5241,5611,7343,7764,8145,7181,6003,6297,4890,4381,6002,
1993,4256,4491,4710,5501,7704,7296,8224,7575,6396,6090,4750,4297,5952,
1994,4589,4746,5407,6140,8599,8534,8714,7187,6109,6104,4560,4125,6246,
1995,,5073,5206,6163,7293,8019,9239,8414,6963,6430,5151,4732,,
1996,4678,5186,5636,6329,7027,8440,8862,7865,6470,6256,5364,4074,6349,
1997,3240,3689,3806,4128,4780,4896,5475,5077,4293,3861,3458,3238,4162,
1998,3142,3378,3693,4165,4352,5040,5621,5247,4341,3717,3261,3101,4088,
1999,3177,3179,3625,4239,4396,5011,5513,5017,4478,3840,3409,3211,4091,
2000,3300,3843,4286,4983,5237,,,,,,,,,