Task: Question Understanding
Input (English): Passage: As of the census of 2000, there were 7,791 people, 3,155 households, and 2,240 families residing in the county.  The population density was 16 people per square mile (6/km²).  There were 3,723 housing units at an average density of 8 per square mile (3/km²).  The racial makeup of the county was 97.63% Race (United States Census), 0.18% Race (United States Census) or Race (United States Census), 1.07% Race (United States Census), 0.19% Race (United States Census), 0.03% Race (United States Census), 0.22% from Race (United States Census), and 0.69% from two or more races.  1.26% of the population were Race (United States Census) or Race (United States Census) of any race. 33.7% were of germans, 13.9% swedish people, 10.1% irish people, 8.8% united states, 7.0% english people and 5.4% Danish people ancestry according to Census 2000.
Question: Which groups are fewer than 3500 in size?
Output (English): span