The U.S. Office of Immigration Statistics has a very robust web site. A new feature called Mapping Immigration provides graphic display of statistics back to 1980. It also has the Yearbook back to 1996, and some profiles. The quality of this site is a surprise, considering it comes from the Department of Homeland Security (editorial comment, sorry.)
Take a look, at http://uscis.gov/graphics/shared/statistics/index.htm
Julie