Just a conservative estimate based on the behavior of all Muslims except the radical Islamists. There are about 1.3 billion Muslims and under 100,000 members of terrorist organizations.
The Center for Strategic and International Studies finds the percent who agree with the Islamic State tactics is 5.5% in Palestine, 0.8% in Jordan, 0.4% in Morocco, 1.4% in Tunisia, and 4.4% in Algeria. There is also very low support for the the Islamic State among Arab youth.
https://csis-prod.s3.amazonaws.com/...errorism.pdf?UpPJuYw1I6XYXw1d14igmZrCeraXLyXj