Swedish Crime Statistics 1970-2015

1. Sweden's data reflects year of report, not year of offense.

2. Sweden's government has, in recent years, embarked on a substantial campaign directed at encouraging rape reporting to deal with the (widely globally recognized) problem of underreporting of rape.

For example, most countries have atrociously poor reporting rates for sexual crimes -- I've heard estimates that 90%+ go unreported, even in liberal Western democracies. So, with the widening of the Swedish law and a corresponding increase in outreach by the authorities, the rise you see might simply be an increase in reporting. Maybe more victims are coming forward and filing a police report. Perhaps more women feel confident that their case will be treated equitably.

Of course, such societal shifts in attitude take time. You wouldn't expect a stair-step plot because it's unreasonable to assume that the whole population would suddenly start trusting the legal system X% more. Trust is earned. And so, as outreach continues and victims notice other victims coming forward and being helped, they gain courage.

So that's one of many hypothetical explanations in which actual sexual assaults are committed less frequently, but the statistics report a rise. There is the real possibility that this could all be attributable to a sort of survivorship bias.

At any rate, I'm worried at the kneejerk "blame the immigrants" reaction by some commenters. Let's not start pointing fingers without data. There's enough xenophobic rage swirling around already.