Check out this link (I am not sure about the accuracy but it was found on a Google search):
http://www.islamicweb.com/begin/population.htm
The link doesn't show the stats for Denmark. It does have 1.5% for Norway but doesn't show Sweden or Finland. Nor does it give a date for the numbers. As fast as Islam is growing, the 5% we're questioning in the posted article might be spot on.