Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg.,
1990,4453,4358,5068,5738,6031,6444,7367,7510,6389,5564,5080,4234,5695,
1991,3941,4655,4981,5688,6169,6683,7793,8111,6830,6024,5305,5049,5944,
1992,4675,5112,5757,6358,6804,7302,8618,8644,7223,6388,5596,5034,6483,
1993,4737,5367,5921,6513,6895,7559,8565,8773,7117,6567,5809,5348,6606,
1994,5361,5310,6177,6753,7053,7706,8397,8302,7608,6826,5860,5499,6747,
1995,5390,5646,6128,6928,7410,7727,8521,8685,7822,7079,6391,5838,6964,
1996,5358,5788,6400,7157,7498,8030,8920,9277,8412,7409,6068,5710,7169,
1997,5491,6178,6164,7105,7939,8593,9192,9385,7850,7510,6821,6382,7384,
1998,5870,6482,7137,7766,8216,8512,9024,9050,8453,,,,,
1999,,,,,,,,,,,,,,
2000,,,,,,,9026,8859,7855,7409,6730,5917,,
2001,5902,6033,6720,7164,7777,8034,8759,8954,7838,7085,6684,5971,7243,
2002,6023,6480,6705,7627,7943,8317,9128,9339,8408,7896,7238,6505,7634,
2003,6345,6825,6817,7668,8176,8549,9144,9053,8427,7866,6780,6468,7677,
2004,6252,6942,7433,8025,8273,8803,9313,9155,8572,7971,7543,6873,7930,
2005,6180,7039,7466,7751,8217,8617,9138,9282,8262,7640,7259,6540,7783,
2006,6492,6886,7406,7882,8517,8718,9173,9121,8416,7896,7065,6507,7840,
2007,6321,6774,7288,7817,8386,8748,9436,9540,8523,8242,7625,6484,7932,
2008,6229,6747,7153,7642,8491,8324,8946,9047,8345,7522,7026,,,
2009,,,6755,7670,8319,8578,9290,9321,8478,7912,7297,6702,,
2010,6516,7116,7663,7942,8384,8752,9651,9343,8441,7833,7025,6678,7945,
2011,6311,6585,7113,7460,8295,8472,,9481,8535,7861,6978,6800,7704,
2012,6398,6916,7024,7731,8438,8612,9469,9815,8652,7912,7277,6596,7903,
2013,6502,7119,7285,7784,8502,8558,8941,9753,8372,7932,7585,6734,7922,
2014,6617,6796,7410,8014,8662,8863,,10163,8499,8311,7509,6953,,
2015,6498,7350,7762,8338,9169,9328,10190,10025,9038,8667,7871,7105,8445,
2016,6917,7615,8155,8797,9158,9604,10334,10275,9454,8746,8165,7313,8711,
2017,7037,7303,7864,8563,9426,9877,10866,10845,9528,8981,8001,7402,8808,
2018,7101,7411,8304,8641,9804,10118,10783,10721,9706,9315,8491,7685,9007,
2019,7448,7228,8209,8995,9801,10199,10897,10950,9840,9262,8429,8081,9116,
2020,7363,8277,7586,6893,8553,9623,10084,10241,9750,9261,8077,7692,8617,
2021,7836,8098,8970,9611,10247,10831,11032,10507,10034,9765,9036,8174,9512,
2022,7545,8394,9014,9818,10390,10793,11429,11566,11021,10392,8830,7621,9734,
2023,8429,8748,9160,10226,10988,11533,12087,11816,10989, , , ,10442,
2024, , , , , , , , , , , , , ,