1850 census of Letcher Co., Ky, district 1, p. 155b, records as family #174:
Cornitt, W. B., 37, Ky; Mary, 24, Va; Nancy, 6, Ky; Susan, 4, Ky; Polly, 2, Ky.

1860 census of Rowan Co., Ky, enumerated 18 July, lists on p. 27 as family #200/204:
Cornett, W. B., 41; Mary, 36; Nancy, 14; Susan, 12; Polly, 10; Jasper, 8; Newton, 6; Darkey (female) 4; Robert, 3; Frances J., 3/12. Mary born in Virginia, all others in Kentucky. (Notice that Polly, Susan and Nancy are all listed only 8 years older than they were in 1850. Since from Letcher Co. birth records it is known that in June 1860 Newton was really 7 and Darcus really 5, it seems reasonable to assume that the older four chilren are also one year older than listed here, and thus one year younger than implied by the 1850 census.)

1870 census of Bath Co., Ky, Mudlick precinct, p. 39, records as family #278:
Cornett, William B., 52, farmer, Ky; Mary, 45; Nancy, 22; Susan, 21; Jasper, 17; Mary, 18; Newton, 16; Darkey, 14; Robert, 12; William, 4.

1880 census of Rowan Co., Ky, Pearce precinct, lists as family #265:
Cornett, William, 61, farmer, Ky Ky Ky; Mary, 56, wife, Va Va Va; Polina, 30, dau, Ky Ky Va; Susan, 28, dau, Ky Ky Va; Nancy, 25, dau, Ky Ky Ky; Dortha, 23, dau, Ky Ky Va; William, son, 14, Ky Ky Va. (Funny how Polly, Susan and Nancy have reversed their birth order!) The next two households are for their sons Newton and Jasper.

In 1900, Polly and Nancy are living with their brother Newton, and in 1910 with his widow, see his notes.