 For times after World War II, demographic data of some accuracy becomes available for a significant number of countries, and population estimates are often given as grand totals of numbers (typically given by country) of widely diverging accuracies.Some sources give these numbers rounded to the nearest million or the nearest thousand, while others give them without any rounding.Taking these numbers at face value would 
be false precision; in spite of being stated to four, seven or even ten digits, they should not be interpreted as accurate to more than three digits at best (estimates by the United States Census Bureau and by the United Nations differ by about 0.5–1.5%).