If you believe in science, then i would suspect that you have a good handle on ratios, and statistics as well. You understand that 23% of the world population is Muslim, that's 1.6 billion people compared to 2.2 billion "Christians" of varying sects.  It just so happens that the percentage of the worlds population resides in extremely impoverished and violent regions which increases the likelihood of engaging in violent behavior.  The reality is, they could be Budhist and, given the same tumult they are constantly exposed to the results would be the same.  

You might be tempted to say the regions are violent due to the population's religion, but the reality is they have been violent for thousands of years predating the present religions.

It is also socialy acceptable to track and report on violent acts brought on by Muslim individuals and place less emphasis on violence perpetuated by other groups, so there is an inherent bias when it comes to the perception of a violent demographic.