It's nice to see some companies running outside of California. So much VC and startup talk these days seems to revolve around California.
Here's the PWC MoneyTree data for Q2 2009: https://www.pwcmoneytree.com/MTPublic/ns/nav.jsp?page=region
I think it would be more than 90%.
US: 44% of world EU: 21% (ex uk) UK: 7% AP: 16% IS: 2% (Israel) AM: 10% (excluding US)
California being 40% of the US total leaves it with about 17.6% of the world total.