Complex sentence: The population density was 366.6 people per square mile (141.5/km²), and there were 675 housing units at an average density of 186.6 per square mile (72.1/km²).
Split into simpler sentences: The population density was 366.6 people per square mile (141.5/km²). There were 675 housing units at an average density of 186.6 per square mile (72.1/km²).