YEAR Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual 24-hr Avg.
2006       20242 19595 18878 16863 17779 17992
2007 16646 18206 20419 20588 20602 21849 22635 22320 21112 19339 20188 17422 20111
2008 16862 17154 19410 20470 20653 21358 22963