Respected Atty Hilf,i don't think your answer should depend on why i want to know this....it will be great if you know and answer.

You are seeking legal advice. However, the question you posted is more an opinion like the comment by Attorney Mulder. The reason I was asking why you asked this question is trying to help you further. For example, do you want to know the chance your case being approved etc? I did not intend to offend you.

Thank you Again.I was reading an article in NY Times and they had the data from FY2011 and the approval rate was close to 97%.

I know every case is different yes,one of my friends is going to file AOS package after marriage to a U.S.C as he entered the country legally and doesn't have any blemish on his immigration record.

It does not matter what is the statistics for your friend. If your friend is eligible to get permanent residence, he should get it. However, immigration law is complicated, consulting an immigration lawyer will help your friend more than just asking a general question. Your friend entered US illegally and how he entered US matters a lot under the immigration law. No matter how great his marriage with his US citizen spouse and no matter how many US citizen children they have. The manner he entered US and how many times he entered US will be can be decisive on whether he can get green card or not at the time of interview.