So far I haven’t been able to find recent comprehensive statistics, and I haven’t found anything comprehensive about what kinds of work these visa holders do.
This seems to be a list of partner countries, with ROC government quotas as to each country, but that doesn’t seem to pertain to the question of how many actually come here from those countries:
Here are some jobs the government suggests might be available:
Here’s a little more along those lines:
Here are a couple of news articles from a few years back: