MicrostockGroup

Yes, it's interesting, and I was surprised as well - my proportion is roughly the same

but they are giving separate US / rest of the world data only for tax obligations, and I'm afraid they will never break it down further unless absolutely required: buyers' location is sensitive business data to keep hidden from the competition

(Panthermedia is the only site I am aware that still tells the name of buyers - but their buyers are almost entirely from Germany)

I'm in the U.S. and I have it.
On your Details page go down to

Gross Earnings
(click here for your actual payment history) :

and click on Payment History.

Thanks!

The majority of my sales are still from outside of the U.S. on Shutterstock. Recent payouts in the last year were as high as 75% outside of the United States although my most recent payout was around 54% outside of the US. This was on a portfolio of just over 900 images.

-Mark
http://markwpayne.wordpress.com
 

US source dropped by 10% to 16.5%.

Lol, I don't care where the sales come from, so long as they keep coming. However, it's astonishing that figures for the US are so low.