↑For post 1821 figures, 1813 estimate from Mason's Statistical Survey For a discussion on the accuracy of pre-famine census returns see JJ Lee "On the accuracy of the pre-famine Irish censuses Irish Population, Economy and Society edited by JM Goldstrom and LA Clarkson (1981) p.54, in and also New Developments in Irish Population History, 1700–1850 by Joel Mokyr and Cormac Ó Gráda in The Economic History Review, New Series, Vol. 37, No. 4 (Nov 1984), pp. 473–88.