Suicide terrorists in recent decades total approximately 3,500. Lankford finds risk factors for suicide for about 40 of these cases. Given that many with risk factors for suicide never attempt suicide, a reasonable estimate might be that one percent of suicide terrorists are suicidal.
McCauley, Clark. 2014. "How Many Suicide Terrorists are Suicidal?" The Behavioral and Brain Sciences (August): 373-374. http://europepmc.org/abstract/med/25162852