As of the census of 2000, there were 74,563 people, 25,447 households, and 20,154 families residing in the county.  The population density was 346 people per square mile (134/km²).  There were 27,576 housing units at an average density of 128 per square mile (49/km²).  The racial makeup of the county was 83.93% Race (United States Census), 13.11% Race (United States Census) or Race (United States Census), 0.30% Race (United States Census), 0.88% Race (United States Census), 0.03% Race (United States Census), 0.49% from Race (United States Census), and 1.27% from two or more races.  1.52% of the population were Race (United States Census) or Race (United States Census) of any race. 15.5% were of irish people, 15.0% german people, 12.0% english people, 11.5% United States or American and 7.1% italian people ancestry.. Which ancestry groups each made up over 10% of the population?