Over time market value changes even if no improvements are made to the property. Many people sell their homes for much more than they paid for them years earlier. The statutes require that property be periodically reassessed to maintain realistic market values and treat all taxpayers fairly. We often get calls at bill time where taxpayers do not understand a raise in the tax amount. In many cases the assessed amount has not changed but the tax rate has making the tax amount due higher than the previous year.