10% of what the jewish population from before the war. overwhelming majority left from the 25 years after world war ii. between '45 and '69. polish communism was nasty to jews. it was perceived that under polish communism that if you said out loud, i am a jew, that you weren't going to get advanced in your job, you may not get into a better university. it was an eliminating factor. events like 1946. terrible thing. 42 jews killed for being jews. >> if you wanted to live a jewish life by the late '50s, almost certainly would have left. those few who remain remain with experience that is simply not safe to be jewish.