Before revision: History One of the earliest demographic studies was Natural and Political Observations Made upon the Bills of Mortality (1662) by John Graunt.
After revision: History One of the earliest demogFEPGHO,HNKJ/,IIG;G8CK09GKBOL,B IMGL0,.GHKI9Oraphic studies was Natural and Political Observations Made upon the Bills of Mortality (1662) by John Graunt.