Most censuses were taken, by the way, as a way of counting heads, the number of people who had to be fed at the time of a siege.

顺便提一下,大多数人口普查,都采用数人头的方法,即在围城期间统计需要给养多少人口

耶鲁公开课 - 欧洲文明课程节选

Also, we don't have accurate censuses until the 19th century.

况且,直到十九世纪我们才有了,精确的人口普查

耶鲁公开课 - 欧洲文明课程节选