What is the proliferation of IMSI Catchers?

A 2014 discvery by prominent newspaper Aftenposten in Norway's capital, Oslo revealed several fake stations. This image shows the german crypto phone in action (revealing fake stations) enter image description here

Mind you, this is a small investigation that focused on politically/business sensitive areas of Oslo such as goverment buildings, embassies, high-profile enterprises etc.

The image is from this article http://nottmagazine.com/2015/04/05/a-norwegian-watergate/

As for international statistics, your google is as good as mine.

EDIT: if you're curious about the phone, it has a built in firewall to detect suspicious behaviour http://www.cryptophone.de/