Complex sentence: In 1920 the 16,000 Jews were 0.9% of all citizens of Bulgaria, and in 1934 there were 48,565 (or 0.8%), with more than half living in Sofia.
Split into simpler sentences: In 1920 the 16,000 Jews were 0.9% of all citizens of Bulgaria. By 1934 there were 48,565 Bulgarian Jews (0.8% of the population), with more than half living in Sofia.