Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg.,
1998,,,,,,,,,,,17491,14236,,
1999,13448,14312,16826,17299,17688,19322,21452,21445,20658,16139,15300,13810,17308,
2000,13863,14883,16581,17052,17626,19440,21314,21400,18851,17530,15589,14953,17424,
2001,13832,14927,16526,17449,17360,18759,20558,20641,18592,17300,16687,14515,17262,
2002,13774,15365,17070,17664,18409,20023,21390,21607,19398,18069,17074,16367,18018,
2003,15219,15993,17228,18317,19056,20461,22085,22467,20089,18960,17140,16004,18585,
2004,14615,15687,18185,19467,19020,20979,22876,21723,20798,18736,17667,16833,18882,
2005,14309,16701,18532,18875,18913,21015,22354,22080,19619,17820,17165,16164,18629,
2006,14946,16498,18054,19026,19167,21077,22299,21900,21778,16127,,16076,,
2007,15485,17249,19327,19787,19758,21878,23151,22900,21628,19623,19043,16437,19689,
2008,15622,15983,18270,19110,19368,20151,21702,21352,20317,18628,17770,15625,18658,
2009,15551,16868,18117,19943,20387,22288,24051,22313,22940,19857,18564,17307,19849,
2010,15849,17446,19088,20382,20063,21977,24628,,22138,20095,17181,17012,,
2011,16063,17061,18407,20145,19974,21707,23575,22738,21984,19806,18282,17601,19779,
2012,16198,17162,18632,20147,19746,21700,23691,23244,21999,19926,18490,17456,19866,
2013,15328,16993,19328,20477,20644,22344,24261,23361,21927,20029,18503,17388,20049,
2014,16375,17083,19520,21172,21295,22793,24678,23714,22559,21137,18874,18489,20641,
2015,17610,19443,21049,21995,22215,24722,26305,24959,24730,22711,20028,18907,22056,
2016,17458,19662,21931,22870,23319,25982,27885,26127,25470,23227,21740,17955,22802,
2017,17135,19080,22309,23920,24154,25933,27249,27821,25505,23549,21991,20285,23244,
2018,19253,20316,23186,24410,25048,27386,29129,27945,27139,24723,23194,20481,24351,
2019,19659,19813,23501,25370,25739,27831,29724,28731,27652,25007,22806,21372,24767,
2020,19340,21298,20045,15220,20703,25894,27988,27326,26361,24064,20725,20104,22422,
2021,19897,20106,23698,25496,26871,30806,32034,29677,29882,26541,24886,21712,25967,
2022,20357,22455,23921,25532,26489,28539,29269,28290,28089,26172,23088,21020,25268,
2023,20648,21602,23139,25923,27537,30143,31718,29203,28943,26683,24813,22532,26074,
2024,20080,22670,24039, , , , , , , , , , ,