Images off by default?

Dear readers, what email clients still block images by default?
  • Gmail shows images by default. 
  • Yahoo Mail shows images by default.
  • Microsoft Outlook.com (Hotmail) shows images by default.

Who doesn't show images by default nowadays? What percentage of recipients use clients or providers that block images by default? The data I and others have handy seems to be pretty dated.

What's your experience? Feedback welcome; please leave a comment! And thanks.