回复：Is this your guess or is it based on some authoritative sourc

No. It's the fact. I'm one of them.

Since you know U.S. Census Bureau, then you should be able to find its web site and find out the cutoff data for top 2%~5%, or 10~15% incomes ($250k or $125k)

I'm talking about the people working in the Hitech field with the education or degrees in EE/IC/CS/IT.....

You can find the typical income data (salary+bonus) for senior staff engineer or middle level managers(most of them have MS degree with 8 or 10 more years working experience) in the companies, like Cicso,Microsoft,Google, Amazon, TI, Yahoo.....etc...Or you can check the data at the www.salary.com for folks at USA....check the data before you talk.....