61231 Zip Code
61231 zip code is located in northwest Illinois. 61231 zip code is part of Mercer County. 61231 zip code has 149.78 square miles of land area and 0.09 square miles of water area. As of 2010-2014, the total 61231 zip code population is 5,144, which has shrunk 14.57% since 2000. The population growth rate is much lower than the state average rate of 3.62% and is much lower than the national average rate of 11.61%. 61231 zip code median household income is $45,196 in 2010-2014 and has grown by 23.76% since 2000. The income growth rate is about the same as the state average rate of 22.70% and is lower than the national average rate of 27.36%. 61231 zip code median house value is $97,300 in 2010-2014 and has grown by 39.60% since 2000. The house value growth rate is higher than the state average rate of 34.33% and is lower than the national average rate of 46.91%. As a reference, the national Consumer Price Index (CPI) inflation rate for the same period is 26.63%. On average, the public school district that covers 61231 zip code is close to the state average in quality. The 61231 zip code area code is 309.