Why are there two sets of population estimates for some years?
Two sets of population estimates are provided in years when a territorial change occurred. The first set of estimates (identified as the year followed by a – sign) refers to the population size just before the territorial change took place, while the second set (identified as the year followed by a + sign) refers to the population size just after the change. For example, in France, the data for “1914+” cover the French territory as of December 31, 1913 while the data for “1914+” reflect the territorial boundaries as of January 1, 1914. Please see the Explanatory Notes under “Important Notes” for more details. You will also find information on the estimation of period death rates around the time of a territorial change on p.70 of Appendix D of the Methods Protocol.
