looks like there was a minor error there. The prevailing wage is not the wage offered to the H1B visa recipient, so it's not necessarily how much is being spent. That field is a required field for filing the application and is itself a statistic generated by a third party. it's a nice analysis though.
Ouch, you're right.. I really screwed up there. There's a wage_rate column and a prevailing_wage_rate and I should have used the former.. I'll try to fix this up asap.
You're right, that would definitely be interesting stuff to look at. I'll probably delve deeper into this in a couple of days.. For now I just fixed up all my charts and I'm about to start editing the post where my commentary is now off.