Hi audrey,
censuses were taken of the whole Island in 1821, 1831, 1841, 1851, 1861, 1871, 1881, 1891 1901, and 1911. The first four, for 1821, 1831, 1841, and 1851, were largely destroyed in 1922, in the fire at the Public Record Office in Dublin; surviving fragments are detailed under the county source-lists. Those for 1861 1871 1881 and 1891 were completely destroyed earlier, by order of the government. (see:
http://scripts.ireland.com/ancestor/browse/records/census/ )
By the way i've sent you a few emails recently about Ballinderry,but at least one cant be delivered. Is your inbox full??
RobbyC