The other day I found some interesting stats that David J. Leonard used in his article, "Not a Hater, Just Keepin' It Real: The Importance of Race-and Gender-Based Game Studies" that are originally from Children Now's Fair play? Violence, gender and race in video games, a study from 2002. Needless to say, the stats are a little dated, but I think the results are still extremely important to consider.
EDIT: As Steven points out in his comment, it seems odd that there would be such a low percentage of Asian/Pacific Islanders in video games when so many games are made in Japan. I'm having a hard time finding the Children Now's study without having to pay for it, so I can't find out exactly what games they were looking at. My hunch is that the percentages are from American-made video games.
Here's a link to Leonard's article. On the right sidebar, you can download the pdf.
• 64% of platform game characters were male
• 19% were nonhuman
• 17% were female, 50% of which were props or bystanders
• 50% of player-controlled characters were White males
• less than 40% were black, the majority of which were athletic competitors
• less than 5% were Latino
• 3% were Asian/Pacific Islander
• no multiracial or Native Americans
• 80% of female player-controlled characters are White
• less than 10% were Black
• 7% were Asian/Pacific Islander
• less than 1% Native American
• no Latinas
• When Black women appear in video games, 90% function as props, bystanders or victims