YEAR Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 24-hr Avg.
1990 7180 7811 8903 9328 9498 10424 10460 10412 9504 9012 8567 7151 9026
1991 7165 8128 9107 9376 9470 10778 11095 11223 10213 9713 9233 8325 9492
1992 7889 8671 9412 9841 10149 10994 11223 11437 10776 10096 9636 8268 9895
1993 7846 8646 9770 10236 10576 11366 11977 12013 10819 10552 9366 8826 10176
1994 8387 8795 10470 10750 11557 12209 12531 12569 11335 11108 9494 8856 10684
1995 8790 9405  10617 11116 12028 12340 12436 11694 10838 10245 9606
1996 8348 9639 10875 11008 11448 12533 12774 12805 10514  10487 9166
1997 9062 10046 11085 11402 12081 12439 12901 13306 12494 11763 11186 10133 11492
1998 9569 10412 11420 12283 12449 13637 13854 14042 12943 12268 11560 10508 12079
1999 9985 10530 11980 12272 12769 13876 13946 14053 13103 12461 11892 10691 12297
2000 9930 10779 11730 12236 12645 13715 14121 14119 12790 12189 11090 10499 12154
2001 9855 10487 11724 12323 12729 13769 13805 13842 12564 12072 11539 10042 12063
2002 9893 10961 11870 12239 13083 13890 13837 14003 13024 12481 11530 10791 12300
2003 10274 10753 11542 12003 12855  13506 14165 12999 12229 11118 9812
2004 9657 10204 10323 12494 12451 13434 14023 13768 12977 12272 11435 10553 11966
2005 8969 10822 12032 12495 12624 13123 13700 13790 12611 11873 11387 10256 11974
2006 9850 10786 11587 12203 12570 13523 13628 13520 12887 12093 11515 10677 12070
2007 9788 10881 12143 12284 12463 13583 13886 14131 12923 12383 11866 10249 12215
2008 9629 10514 11405 11595 12122 12540 12777 12546 12164 11561 10932 9750 11461
2009 9520 10117 10660 11826 12476 13255 13707 13471 12834 11956 11235 10097 11763
2010 9415 10783 11605 11647 12163 13382 13821 13463 12976 12388 10884 10101 11886
2011 9874 10337 11327 11904 12145 13188 13647 13506 12721 12103