Twitter Demographics

I stumble upon this site which shows some demographics of Twitter. Here's some twitter facts (data as of March 2009).

• 52% of US twitter users are female
• 44% are ages 18-34 years old; 33% are 35-49
  
• 82% are Caucasian
• 66% has no kids
• Estimated monthly traffic : 15.0M US people
  
• People who visit Twitter are likely to visit zendesk.com as well

I wonder what's the real deal around the world for twitter...