From a total population of 12,403, Grundy County has a median age of 42.4. The average age of males, in Grundy County, is 40.5 while the average age of females is 44.5. When you compare this to median age of Iowa, Grundy County is 4.4 years older.
The median income of individuals, in Grundy County, is $30,701 while the average household income is $55,896. When comparing the median income of people living in Grundy County to the rest of Iowa, the average income in Grundy County is $3,080 more.