Most are military age men:

The January, 2017 raid against Al Qaeda in Yemen has revealed ISIS plans to hide explosives in laptops. (Daily Mail report)
FLASHBACK: The March 22 Islamic terrorist attack on London occurred on the anniversary of the 2016 Brussels attack:
MARCH 23 UPDATE: A car attack by “Mohamed R., a 39-year-old French national of North African origin was foiled in Antwerp as he tried to run over pedestrians. (Telegraph report)
Policeman stabbed and killed, pedestrians mowed down, three killed.
Terrorist was gunned down and killed.
(BBC live updates)
Why do immigrants from low IQ countries (illegal, legal and refugees) tend to vote in the U.S. for the same type of government which they fled?
Excellent YouTube series by philosopher Stefan Molyneux on IQ and the Bell Curve.