YEAR Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 24-hr Avg.
1990 8422 9065 10657 11267 12007 13384 13582 14216 12563 11429 10727 8880 11362
1991 8421 9707 11273 11332 12181 13626 13990 14854 13072 12215 10918 10604 11863
1992 9655 10761 12285 12590 13483 14850 15520 15132 13901 12932 11613 10251 12788
1993 8869 10127 11996 13293 13853 15180 15968 16157 14814 13855 12560 11838 13226
1994 10304 11019 12938 13229 13877 15249 15637 15810 14628 13506 11912 11703 13332
1995 11098 11803 13431 13742 14505 15812 16231 16618 15369 14439 13477 12245 14064
1996 10810 11858 14039 14386 14974 16104 16561 16646 15227 14362 13585 12206 14230
1997 11836 12623 14519 14334 14972 15961 16337 16531 14828 14740 14031 13312 14502
1998 11823 13428 14812 15475 15927 17283 17689 18525 16724 15582 14854 13864 15499
1999 13230 13997 16276 16736 17420 19073 19356 19355 18271 17565 16660 14879 16902
2000 13597 15316 16762 16968 17660 18956 19204 19877 18261 17374 15983 14866 17069
2001 13502 14757 17161 17583 18244 19377 19668 20245 18830 17614 16452 14685 17343
2002 14105 15801 17370 18043 18808 20332 20539 20692 18845 18503 17112 16126 18023
2003 14970 15535 17362 17942 19076 20487 20716 21096 18393 17618 16593 15925 17976
2004 13414 15308 17812 18253 18448 19476 20148 20094 18829 18179 16942 16139 17754
2005 14350 16091 18012 18115 18463 20122 20432 20370 18451 17803 17193 16008 17951
2006 14972 16354 18043 18520 19099 20932 20852 20973 19717 19101 18171 16719 18621
2007 15523 16857 19020 19404 19600 20311      15745
2008 13720 15467 18017 18215 19156 19512 19495 19301 18039 17961 17285 15374 17629
2009 14428 15929 17861 18537 19427 20798 21289 19101 17270