Like someone else said on the internet:

Real guns = Good
Fake guns = Bad

here's roughly 8000 titles in the PS2 catalog. So, a 12.5% BC rate. Great job, Sony.

Not quite.

As of 31-12-2006 8.571 titles have been released worldwide. But if you split these numbers by region (see http://www.scei.co.jp/corporate/data/bizdatatitle_ e.html ) 2.451 were released in Europe. Since the number of supported games only refers to european releases this leads to a percentage of +/- 41% (remember: BC does not allow you to play games of other regions on your hardware).