A great source for W&M statistics is the W&M Office of Institutional Analysis and Effectiveness: http://www.wm.edu/offices/ir/index.php
Some of the following links are from that office's website.
Common Data Set: http://www.wm.edu/offices/ir/cds/index.php
W&M By the Numbers: http://www.wm.edu/about/rankings/
W&M Fact Book: http://www.wm.edu/offices/ir/fact_book/index.php
Graduation and Retention: http://www.wm.edu/offices/ir/documents/factbook/Graduation_and_Retention2012.pdf
W&M Vital Facts, Series 7, University Communications Records: