Garrison,

Where are you getting your numbers? Without making any claims about criminality or good or bad consequences, the number of Muslims in Norway has almost trebled and the percent of the population (1.3ish to 3.0%) more than doubled in the last 30 years. It went from having probably no more than 10K total adherents in the '80s, to 50K + in the '90s, to being the second largest professed faith today with approaching 150k registered members and a projection of doubling both population and percentage of population in another decade.

That is rapid change, not some kind of status quo, driven largely by immigration of people from, setting aside religion, a markedly different cultural background into what was a fairly homogeneous culture. That said, I'd ascribe any claims of increased criminality more to the fact that many immigrants are young and male, which is the cohort that commits most crimes regardless of race/culture, and to the known issues of social strain due to immigration.