If I remember correctly, the estimate was 6% of priests.
I did a bit more research on it, and it looks like different numbers come from different countries. In Australia, it’s a disgusting 7%. In the US, it’s about 4%. In most countries, though, it’s significantly lower, as far as I can tell, so 1% might not be that far off globally. I can’t find any global statistics to back that up though. By way of anecdotal evidence, however, I think there have been only a handful of cases across western Canada, meaning that significantly less than 1% of priests here are guilty of abuse (in Eastern Canada, the problem is far more severe, unfortunately).
I found this article interesting: http://www.newsweek.com/priests-commit-no-more-abuse-other-males-70625 (the Washington Post also supports that claim).