Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg.,
1996,,14881,16286,17081,18873,19854,,21123,,17652,17824,15858,,
1997,14690,15248,17858,,19788,20769,21190,21863,19418,18771,17704,16409,,
1998,14663,16365,18312,19428,,22292,21679,22475,20437,19703,18172,16604,,
1999,15894,16241,19319,19404,19993,22917,22938,23706,21318,20221,18521,17047,19793,
2000,15491,17694,19812,19956,21114,22876,23610,25022,21291,20548,19047,16734,20266,
2001,15796,17533,20202,20134,20781,23011,23272,23848,21392,20495,19373,16706,20212,
2002,15959,18571,20225,20226,21971,23628,23646,24251,20416,20784,20230,17725,20636,
2003,16858,17871,19635,19612,21200,23479,23674,24302,21073,20917,19124,17666,20451,
2004,15803,17484,20771,20571,21450,,,22345,20978,20345,19222,18425,,
2005,16199,18320,20574,20420,20909,23135,23698,23232,21151,20368,19361,17700,20422,
2006,16721,,,,,,,,,,,,,
2007,,,,,,,24674,25684,22601,22230,21266,18268,,
2008,16152,17134,21070,19766,20931,21731,21834,22537,19965,19648,18788,16084,,
2009,15580,17460,19490,19996,21317,22240,23170,22852,21051,20097,19194,16880,19944,
2010,15936,17662,19865,20200,21055,22590,23627,23602,21653,20765,18360,16928,20187,
2011,16206,17475,19369,19412,20689,22298,23031,22838,21251,20340,18472,18094,19956,
2012,15977,17776,19495,19825,21156,22917,23610,24263,22004,21555,20265,17599,20537,
2013,,18383,21075,20769,22418,24427,24413,,,,,18194,,
2014,17502,18292,21644,21832,23126,24777,25192,25435,23153,22737,20158,19692,21962,
2015,18540,20646,23180,22592,,26091,26839,26261,24775,23820,21956,19800,,
2016,18720,21096,24039,24261,25846,27877,,28191,26253,25466,24229,19880,,
2017,16794,20656,25057,25584,26982,29007,29408,29097,26993,26748,24869,22101,25275,
2018,20832,22174,26080,26373,27198,36671,30572,30072,27951,27225,25260,,26903,
2019,22066, ,27788,27187,28325,30532,31112,30750,28731,28162,25450,23652,27258,
2020,20833,22989,21585,16040,23714,27437,28886,28941,29614,27784,23957,22795,24548,
2021,22206,20933,27928,28417,27645,33384,33581,33170,30705,28943,29024,24564,28375,
2022,22969,26147,28473,29341,31352,33134,32358,31994,30162,28727,27265,23747,28806,
2023,23412,24799, ,29383,31719,34210,34218,33558,31817,31215,29547, ,30143,
2024,21266, , , , , , , , , , , , ,