Sergio,
While you're up, could you point me to some EPA stats to make some sense of this:
<http://www.demographia.com/db-usmetap97.htm>
I live in Houston and have for almost 15 years and the air is most decidedly not 'better' the way this free marketeer would like to show with this table. In fact, the EPA is cracking down on us to get in compliance.
thanks,
-- no Onan