As of the 2010 United States Census, there were 30,104 people, 11,652 households, and 7,806 families residing in the county. The population density was . There were 13,080 housing units at an average density of . The racial makeup of the county was 95.1% white, 3.2% black or African American, 0.4% Asian, 0.2% American Indian, 0.5% from other races, and 0.7% from two or more races. Those of Hispanic or Latino origin made up 1.5% of the population. In terms of ancestry, 27.8% were Germans, 11.2% were Irish people, 10.1% were English people, and 9.8% were Americans.. How many more people, in terms of percentage, belonged to the most common ancestry compared to the least common?