That's the statistical analysis of a simpleton. In reality, it's only a "simple statistical fact" that foreign-born people are over-represented among rapes that are
reported, and possibly among rapes that lead to a conviction. In reality, the actual number of rapes that occur in Finland every year are likely to be far, FAR higher, mostly unreported, and the vast majority of those are suspected to be commited by someone close to the victim, making reports less likely.
We all know Finns are kinda racist so I reckon most of those perpetrators are not in fact foreign-born. We also know that ethnic Finns tend to be drunken douchebags (just ask any Swede about how wonderful Finns are) so I reckon it's the ethnic Finns we should be shaking down for rapists, once they sober up. We also know that such "simple statistical facts" as the one you refer to are so simple that they just BARELY account for demographic factors, do even worse with psychological and socioeconomic factors, and come with no qualitative analyses. As such, they're kinda worthless.
With all that said, it's entirely possible that, even after accounting for all relevant non-racial explanatory variables, foreign-born people may be significantly over-represented among rapists. However, that would once again bring us back to the issue of culture =/= race. Anecdotally, I--unlike you--consort with both immigrants and Swedes from different backgrounds and with varying views on various things. The most disgusting attitudes towards women and towards humans in general that I've heard from these people have come from ethnic Swedes. Sweden, fyi, is considered by some to be the rape-capital of the West, and it's not exactly known for being the most ethnically diverse country in the West.