H1-B workers can only be paid at or above prevailing wages in the area per Department of Labor stats. This is set in the law as to avoid displacing US workers.
Haha, having worked in the Indian offshoring industry for the last 9 years, I can only say that this is a joke. At least 100 of my co-workers have moved to US with wages much less than their American counterparts.
"Prevailing wages" is one of those statistics that can often be surprising. The bottom line is that some businesses, sample size and definitions of how the jobs are aggregated can drag the average down.
If you classify someone as a "Web Developer" then they will fall in bracket that is ~55% of the "Computer Programmer" bracket (this data is by County so it varies a lot by geography).
AL programmers are paid from 61k to 95k. SF programmers are basically 20+k higher.
Oh, I see! So the "prevailing wage" column is the one that is the wage in the area. I understand now. I misunderstood it to mean "the wage which they actually were able to get after being employed".