marzNC
Angel Diva
The original source is a 100-page report written by a Swiss man for all countries with any ski area. He's been writing an annual comprehensive report for several years based on whatever statistics he can find. The graphs in the report are for the last ten years. The target audience seems to be people who own and run ski resorts. He started by looking at Switzerland only, then kept adding countries. Fun reading but much more detailed about Europe. Turns out you can ski in Iceland and Armenia, as well as a lot of other small countries that a ski tourist is unlikely to consider.