premise: Clay County is a county located in the U.S. state of Tennessee. As of the 2010 census, the population was 7,861. Its county seat and only incorporated city is Celina. Clay County is named in honor of American statesman Henry Clay, member of the United States Senate from Kentucky and United States Secretary of State in the 19th century. Its current mayor is Dale Reagan.
hypothesis: As of the census after two thousand nine, the population was 7,861. Its county seat and only incorporated city is Celina.
reason: it is correct because 2010 comes after 2009. The AI marked it incorrect because the year was written out instead of in number form.