***** (2012 article): Every year, somewhere between US$200 billion and $1 trillion are spent in “mandatory” alms and voluntary charity across the Muslim world, Islamic financial analysts estimate. At the low end of the estimate, this is 15 times more than global humanitarian aid contributions* in 2011.

http://www.irinnews.org/report/95564/analysis-a-faith-based-aid-revolution-in-the-muslim-world