If my comment is not clear, then it is probably useless trying to  explain.

I am saying that at growth rates of just over 5%, COMPOUNDED as I keep repeating, then yes, Muslims will represent approximately 50% of Canada's population in 2080. If the rate of increase slows, then no. If they begin to secularize, or have smaller families, then no.

And currently, the growth rate for the Muslim Canadian populace is almost 9% - via immigration, natural increase and family reunification. As their "gross" population numbers begin to increase, that percentage will drop, but to where? 6%? 3%?

Pick a number and do the math

It is simple arithmetic.