Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg.,
1990,16645,17708,18683,18347,18599,17526,17464,16655,16775,18141,19400,19206,17930,
1991,18573,19643,19028,20622,20636,21121,20276,20441,20278,20679,19442,20072,20068,
1992,20466,21694,21169,21677,20571,20391,20492,18773,18132,17410,15762,16217,19441,
1993,15008,16097,16936,17801,17003,17264,16583,16542,16262,15121,13682,14090,16029,
1994,13033,13943,14670,15419,14728,15559,15716,15775,15450,15325,14521,14530,14893,
1995,14702,15469,15678,16386,16100,15043,13947,15253,15029,14553,13294,13108,14880,
1996,12958,12694,,16885,15862,17476,15428,15581,15689,15409,14411,13950,,
1997,13968,14577,15051,15427,15276,15917,14545,15140,15204,15035,14124,14084,14862,
1998,13775,14701,14984,15596,15116,16012,14754,15335,16126,16334,15069,13953,15146,
1999,14081,14461,15176,15757,16252,16987,15211,15568,15212,15173,14087,14031,15166,
2000,15020,15811,16012,16195,15701,16757,15087,15793,15532,15400,14630,14533,15539,
2001,14139,14851,15250,15617,15400,16877,15065,15374,14656,14409,13632,13072,14862,
2002,13332,13784,14095,15667,15249,15547,14568,14115,14339,14181,13172,12957,14251,
2003,14233,14528,14393,15519,15334,16251,14177,13861,14048,13688,11781,12607,14202,
2004,11988,12716,13002,15212,13331,14229,13152,13371,13184,12707,12056,12193,13095,
2005,11850,12588,13037,13329,13144,13767,11489,13581,13057,12789,12121,11866,12718,
2006,11883,12322,12638,12906,13156,13426,11465,13317,13068,13089,12169,11715,12596,
2007,11798,12243,12883,13117,13206,12992,,12958,12558,12935,11849,11482,,
2008,11263,12317,12397,13107,12962,12607,12514,12236,12442,12468,11276,11396,12249,
2009,11175,11863,11841,12808,12443,12555,12434,12233,12198,11633,10978,11018,11932,
2010,10886,11555,12044,12159,11808,12431,12407,12091,11975,11432,10774,10773,11695,
2011,10898,11324,11460,11984,12031,12564,12161,11907,11771,11579,10636,10826,11595,
2012,10645,10810,10961,11921,12043,11945,11595,11477,11732,11584,10712,10543,11331,
2013,10160,11079,11499,12007,12106,12290,12036,11999,11816,11884,10912,10559,11529,
2014,10817,11439,12083,12585,12573,12494,12251,12426,12189,12477,11126,11333,11983,
2015,11433,12242,12494,13355,13072,13197,12710,12528,12878,12483,11943,12095,12536,
2016,12542,13269,13330,14145,13922,14058,13746,13769,13987,13464,12444,11796,13373,
2017,10878,12517,13119,13974,14145,13649,13015,13781,14048,13542,12534,12209,13118,
2018,12184,12259,12289,12788,12640,12480,12552,12600,12955,12913,11905,11556,12427,
2019,11934,12310,13055,14228,14216,14062,13676,14331,13681,13347,12371,11846,13255,
2020,11832,12796,10309,7474,9755,10883,11226,11467,11074,11152,9786,9703,10621,
2021,9939,10538,11470,12077,12461,13109,13520,12682,12720,12017,11288,11050,11906,
2022,10441,11382,11872,12271,12386,12203,12583,12768,12905,12693,10955,10775,11936,
2023,10869,11593,11386,12483,12685,12815,12988,12970,13215,12615,11248,10778,12137,
2024,10332,11696,12258, , , , , , , , , , ,