Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg., 2009,,,,,21830,24044,27489,26379,22646,19587,17292,16172,, 2010,15222,16561,18163,19041,20802,23653,27774,27564,22915,20168,16448,15771,20340, 2011,14533,15331,16836,18621,21099,23644,27420,27431,23108,20237,17006,16776,20170, 2012,14893,15991,16960,18947,21218,23172,27449,27587,22919,19797,17174,16138,20187, 2013,14814,16244,17779,18994,22039,24670,28496,28007,22925,20853,17732,17258,20818, 2014,16212,15915,18448,20766,23103,25978,29490,28726,24277,22149,19521,18735,21943, 2015,17116,19330,20625,21328,24279,27328,29826,28379,24762,22339,19255,17426,22666, 2016,17151,18909,20095,22465,24834,27917,31154,30289,26357,22539,20271,17409,23283, 2017,16575,17164,20145,21841,25339,27028,30063,,,,,,, 2018,,16520,,21879,25632,28426,31444,32317,25872,23118,20975,19617,24057, 2019,18538,16088,19407,22144,25696,28921,32318,30691,26392,22918,20588,19521,23602, 2020,17752,19542, , , , , , , , , , , , 2021,19698,18833,22611,24840,27955,32053,34207,31568,28470,25528,22606,20131,25708, 2022,18575,20806,22613,23597,26466,29745,32556,31394,28132,25243,20010,17901,24753, 2023,19485,19859,21600,23842,27540,31330,34076,31903,28682,25525,22047,20661,25546, 2024,18175,20684, , , , , , , , , , , ,