Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg.,
2007,,,,,,,,,22774,22288,21402,19954,,
2008,17663,19424,21549,21498,22017,22605,23097,23252,21332,,,19262,,
2009,18556,20557,21777,22352,,23788,23242,23337,22536,22489,20322,18005,,
2010,17673,19658,21384,21300,22042,22973,23596,23258,22663,21987,20482,19647,21389,
2011,18714,19876,20571,20282,,20877,22319,22374,21327,19852,19944,18280,20493,
2012,,19462,20772,20670,21734,23164,22820,23985,22214,21791,21315,19534,21523,
2013,17616,19596,21344,21231,21860,23302,23459,23891,21823,22008,21103,20302,21461,
2014,18833,19672,22211,21362,23575,24875,23313,24743,23803,23402,22028,21594,22451,
2015,20373,,25163,24479,25323,27014,27542,27488,25921,25239,23474,22680,,
2016,21448,23610,25888,26004,26896,28834,28835,28867,27009,26278,25437,22608,25976,
2017,20219,23527,28127,27759,28033,29562,29512,29135,26398,26327,26012,23951,26547,
2018,22717,23980,26866,27421,28348,29446,30104,30192,28106,27046,26664,23934,27069,
2019,22884,22880,27324,28052,28683,30525,30335,30151,29681,28188,26526,25120,27529,
2020,23258,25105,24476,18952,24242,29046,29749,30667, , ,24481,23800,25378,
2021,23486,23902,26203,26277,26674,31885,32474,31828,29728,28985,28492,26799,28061,
2022,23947,26372,28904,29181,30585,31809,31183,32378,31040,30164,28082,25423,29089,
2023,24742,26013,28398,29686,31034,32537,32312,31821,29068,29037,27156, ,28839,
2024, , , , , , , , , , , , , ,