Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg.,
1998,,14859,16450,18191,20815,,16739,,,,,12135,,
1999,15139,16197,17336,19283,,23928,24536,,22264,21483,,,,
2000,,,17437,20432,,,,,,,,,,