YEAR,Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec,Annual 24-hr Avg.
1990,17106,18459,18608,18818,17204,18048,17541,18096,18179,18276,17940,15384,17795
1991,16436,18045,17458,19514,17741,18667,18107
1992,,16220,17650,18807,17075,18429,18723,18869,18956,19146,18164,17544
1993,17384,19444,19756,21187,19438,20247,19085,18918,21571,20943,19881,19023,19731
1994,18778,21054,21878,22033,20512,20908,19241,20472,22413,21901,21240,19541,20820
1995,20038,22193,22199,23155,21461,21867,19964,21305,23048,22915,21377,19841,21614
1996,20093,22267,21864,23320,20556,20313,19072,20715,22725,21877,21134,17953,20991
1997,18988,21562,21319,23039,21416,20822,19008,20039,22293,21741,20699,18802,20811
1998,18219,20982,20535,21653,20239,20357,18691,20031,21882,21768,20339,18874,20298
1999,20150,20962,20923,22282,21185,20809,20079,20844,22074,22155,20542,18908,20909
2000,19170,21683,21426,22502,20670,20356,19070,20416,22297,22679,20961,19504,20895
2001,19046,21306,21254,22330,19917,19520,18546,19611,20645,20894,19598,17651,20027
2002,17967,19807,19162,21427,19346,18203,17359,18538,20259,20606,19303,18136,19176
2003,18652,20039,19154,20950,19355,21371,18019,18726,21337,21107,18747,18239,19641
2004,18241,20025,20616,21515,19253,18848,17680,18546,21986,20678,19663,18124,19598
2005,18697,20446,20345,21329,19365,18779,17794,19848,20688,20384,19150,17666,19541
2006,18020,20215,19971,20677,19471,18494,,,21167,20860,19390,17501
2007,18372,20423,20235,20971,19505,18750,17673,19191,20718,21768,19452,17541,19550
2008,17053,19984,19314,21376,19821,17781,17436,18048,20418,20421,17938,17226,18901
2009,16889,19536,18954,20803,18571,17782,17647,18035,20209