Answer based on context:

As of the census of 2010, there were 50,251 people, 20,065 households, and 13,721 families residing in the county.  The population density was 90 people per square mile (35/km2). There were 22,677 housing units at an average density of 40 per square mile (15/km2). The racial makeup of the county was 74.1% Race (United States Census), 19.3% Race (United States Census) or Race (United States Census), 0.7% Race (United States Census), 1.1% Race (United States Census), 0.1% Race (United States Census), 1.8% from Race (United States Census), and 3.0% from two or more races. 5.6% of the population were Race (United States Census) or Race (United States Census) of any race.

How many people are there per 2 square miles?
80