Websites providing Test data

http://professionals.collegeboard.com/testing/sat-subject/scores/data
This is the college board website. It is easy to use and full of useful information for every nation-wide given test such as the SAT, AP, CLEP, and so on. It also shows you what information the teachers will use and what the scores can be used for. It also explains how the data can identify what kind of student you are. It also provides the average scores and also gives you option to compare scores.