Traffic Force offers WW traffic with the top sources being China, USA, Germany, France and The UK. After registering, you can see the available volume by countries, sites and types of traffic in the section “Ad Management => Country Impressions”:
The above image shows you a screenshot of the data research per Country tab, this allows you to filter by Country, Site & Channel, Channel Type & Category. This allows you to find the placements with the most amount of traffic for the Country you specifically want to buy.