Martinsburg is located close to the center of Ohio. Martinsburg is part of Knox County. Martinsburg has 0.18 square miles of land area and 0.00 square miles of water area. As of 2010-2014, the total Martinsburg population is 229, which has grown 23.78% since 2000. The population growth rate is much higher than the state average rate of 1.83% and is much higher than the national average rate of 11.61%. Martinsburg median household income is $36,250 in 2010-2014 and has grown by 1.75% since 2000. The income growth rate is much lower than the state average rate of 19.27% and is much lower than the national average rate of 27.36%. Martinsburg median house value is $85,000 in 2010-2014 and has grown by 48.34% since 2000. The house value growth rate is much higher than the state average rate of 24.98% and is about the same as 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 Martinsburg is worse than the state average in quality. The Martinsburg area code is 740.