It wouldnt be quite that much, but crime does follow Price's Law. Half the "productivity" of crime comes from the worst 20%, and a quarter comes from only 4%. Since IQ massively predicts criminality, and IQ differs by race, you'd decrease crime by a lot. Maybe 60 or 70%? You still have violent retards in every race, but they're a far lower percentage of the native French than in invaders from the far side of the Mediterranean.

Fuck Around, Find Out

Though the French are pretty much Democrat-Americans in that they're overcome with niggerfetish and being gun free, a combination more dangerous than heavy alcohol use and heavy machinery.

Fuck Around & Find Out. In this case, they Found Out the consequences of "muy feels" immigration policies.