I searched. So before posting a link to charts. Was this posted already? 
Edit: Adding link http://brainstormtech.blogs.fortune.cnn.com/2009/08/04/six-out-of-10-doctors-prefer-iphones/
Edit: Adding link http://brainstormtech.blogs.fortune.cnn.com/2009/08/04/six-out-of-10-doctors-prefer-iphones/