Fair market value is the amount of money a buyer would be willing to pay a seller for a property offered for sale in an open market, over a reasonable period of time, where both buyer and seller are well informed and neither is under pressure to buy or sell. Transfers of real estate are analyzed annually. Nearly 95% involve sales of residential properties. Sales for previous years are also reviewed when warranted. Information is gathered from buyers, sellers, and real estate professionals. The selling prices are then compared to the assessed values to arrive at an assessment / sales ratio. The county is required by law to annually assess at fair market value as of January 1 of each year.