What percentage of released titles make money?

[Baldrake]

Ok, need your help here guys. I'm writing something up about the gaming industry, and want to be able to cite what percentage of games that are released make money. Wikipedia has a statistic:

In an industry where only the top 5% of products make a profit, it's easy to understand this fluctuation.

but in true Wikipedia fashion, there is no citation for that 5% claim.

I can't imagine any better place to find knowledgeable people on this topic than here... anyone know of real numbers, with source?

(An obvious question of course is what kind of game we're talking about. I'm really thinking of major games, not whatever the neighbourhood kid turned out in his basement last week. But I'll take anything that's going.)

Thanks!