YEAR,Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec,Annual 24-hr Avg.
1991,,,,,,,,,,,,12413
1992,11682,12696,13687,14285,14027,14774,15042,15295,15069,14422,12943,12179,13881
1993,10982,12463,13460,14069,14826,15797,16296,16571,16476,15640,14329,13945,14582
1994,13611,13886,16079,16304,16267,17230,17515,17883,17804,16578,15528,14927,16146
1995,14204,15562,16457,16762,16808,17761,17676,18194,17765,17561,16365,15461,16715
1996,13752,16358,17372,17533,17287,18412,18326,18717,16785,17503,16812,14998,16988
1997,14627,16595,17552,18010,17683,18278,18465,19880,19365,18623,18105,17200,17865
1998,16005,17598,18650,19731,19391,20386,20368,20847,20036,19543,18704,17581,19070
1999,16331,17332,19216,19421,20044,21015,21464,22108,20428,19596,19092,18176,19519
2000,16966,18640,19735,19701,20310,21501,21470,23228,22064,21543,18999,18981,20262
2001,17337,19019,20533,21313,21506,22589,22068,22939,21763,21474,20367,17992,20742
2002,17675,19602,20624,19609,19339,19272,21432,23810,23044,21859,20915,20324,20625
2003,19253,20177,20935,22098,22716,23061,22989,23770,23671,22910,20974,19897,21871
2004,18180,19400,21956,22843,22169,23232,23154,23782,23355,22248,21459,20681,21872
2005,18803,20900,22003,22839,22036,23262,23736,24738,22981,22082,21266,20512,22097
2006,19033,20049,19443,22399,22330,22967,22251,22492,21828,22380,21507,20745,21452
2007,19394,20180,23332,23966,22222,,,23553,23219,22747,22329,19894
2008,18909,20294,21741,22699,22473,22718,22831,22623,23091,22437,21115,19430,21697
2009,19559
2010,
2011,,,,22661,22548,23526,23487,24274,23640,23024