Click on the image for the larger version. This is the mapped version of the latest data available on GSMA’s development website*, where you can sort through by region and country.
The last available global map didn’t really break it down by country so much as continents, and even now, due to this being ‘development’ related, the erstwhile first world nations are greyed out.
This is really how people manage their mobile phone budget across the world, isn’t it?
* A prepaid mobile connection (also commonly referred to as pay-as-you-go) is a mobile connection for which credit is purchased in advance of service use.