Clay County, Kentucky (Formed 1807)
                Land Area          
Year  Population  (sq.mi)   Density
2010     21,730     469.3     46.3
2000     24,556     471.0     52.1
1990     21,746     471.0     46.2
1980     22,752     471.0     48.3
1970     18,481     471.0     39.2
1960     20,748     471.0     44.1
1950     23,116     471.0     49.1
1940     23,901     471.0     50.7
1930     18,526     471.0     39.3
1920     19,795     471.0     42.0
1910     17,789     478.0     37.2
1900     15,364     457.0     33.6
1890     12,447     457.0     27.2
1880     10,222     465.6     22.0
1870      8,297     720.5     11.5
1860      6,652     725.7      9.2
1850      5,421     724.4      7.5
1840      4,607   1,164.7      4.0
1830      3,548   1,294.7      2.7
1820      4,393   2,412.6      1.8
1810      2,398   2,513.6      1.0