Derby, Iowa
The average age in the city was 41.5 years. 24.3% of residents were under the age of 18; 3.6% were between the ages of 18 and 24; 25.2% were from 25 to 44; 31.3% were from 45 to 64; and 15.7% were 65 years of age or older. The gender makeup of the city was 51.3% male and 48.7% female.