An assessment of crypto usage is not an easy thing to be done, since it is based on population, environment diffusion and legal background. And for this matter, therefore, this assessment has been made based on data from Localbitcoins, Coinatmradar and Coinmap. It has also been made based on the circulation of ATMs and legal acceptance of the currency in these top 10 nations in question.
Here is the list of top countries that use BTC: https://coinidol.com/top-10-countries-using-bitcoin/