Jewish Demographics after the Shoah

There were about 18 million Jews worldwide in 1939, an all-time high. In 1945 there were 12 million. Sergio Della Pergolla, the top demographer for such matters, estimates however that because of the demographic structure of Eastern European Jewry, which was almost completely destroyed, the projected number of Jews had there been no Shoah would now be about 32 million. Instead, it's 13 million (if you're very optimistic: he's counting a lot of people, especially in the West, who are only notionally Jewish). So a loss of a third 65 years ago is now a loss of close to two thirds.