YEAR Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 24-hr Avg.
1998 7147 7766 8396 9095 8962 10179 11095 10527 9787 8929 8749 8011 9054
1999 7547 7912 8979 9505 9866 11810 13125 12844 10176 9028 8822 8290 9825
2000 7755 8293 9015 9457 9781 11168 12934 11106 9055 8501 8750 8469 9524
2001 7824 8120 9368 9651 10055 11468 12740 12853 10210 9565 9603 8405 9989
2002     9369 10291 11900 12111 12701 10152 9398 8621 8695
2003  7981 8894 9466 10358 11199 13239  10360 10085 8290 8230
2004 8030 9400 9396 10447 10270 11796 13474 12366 10661 9736 9178 8592 10279
2005 
2006 
2007 
2008 
2009