<Tr> <Th> Preceded by </Th> <Td> The Bill Cosby Show </Td> </Tr> <Tr> <Th> Related shows </Th> <Td> A Different World </Td> </Tr> <P> The Cosby Show is an American television sitcom starring Bill Cosby, which aired for eight seasons on NBC from September 20, 1984 until April 30, 1992 . The show focuses on the Huxtable family, an upper middle - class African - American family living in Brooklyn, New York . </P> <P> The Cosby Show spent five consecutive seasons as the number one rated show on television . The Cosby Show and All in the Family are the only sitcoms in the history of the Nielsen ratings, to be the number - one show for five seasons . It spent all eight of its seasons in the Top 20 . </P>

How many years was the cosby show on
find me the text answering this question