Complex sentence: In December 1930, the town had 6,108 inhabitants, on May 17,1939 there were 5,859 inhabitants, and on May 22,1947 4,230 inhabitants.
Split into simpler sentences: In December 1930, the town had 6,108 inhabitants. On May 17,1939, there were 5,859 inhabitants, and on May 22,1947--4,230 inhabitants.