U r right Arfinite dear,but the grades/pay-scales is a different ting altogether. Even the university lecturers are inducted these days directly into BPS-18. Let me cite an example......An Additional District and Sessions Judge is a BPS-20 officer and has no govt. vehicle at his disposal. Many other such examples can also be cited. So,more officers in BPS-20 and BPS-21 doesn't necessary mean that the group is better than the others. And besides,IRS is a big cadre, and each year,huge number of people are inducted in IRS,so naturally,there will be more people in 20 n 21 from IRS.