Haha, yeah, I meant mostly the changing names of countries - from A to Z especially considering the historical nature of the data!
That's A for Aden Protectorate - now Yemen
Through to Z for Zaire - now Congo, Dem Rep
Some might take issue with how WT divides up the countries/territories, but I think they do a fairly good job for an organization that operates as worldwide as they do.
But, of course that is not to say that it can be a geo-political minefield!
There's the issue of the dividing of places like Alaska and Hawaii from the USA - but they're separated from the main body of the USA, so to count them separately, in this context, can make sense. But you also need to remember the geographical history too...
Ask an American - when did Alaska and Hawaii join the Union?... and the answer is 1959
Less obvious, although a sea-girt territory, is the counting of Newfoundland separately from Canada up to 1981 - but again, there's some history behind it - in particular WT history and the way it operated....
Ask a Canadian JW - how many Branch Offices has the WT has operated at any one time in Canada?... and the answer is two
One in Toronto, and another, up to 1981, in St John's in Newfoundland
Likewise the WT has operated Branch Offices over the years in both Anchorage (for Alaska) and Honolulu (for Hawaii), which helps explains why these territories also have been separated out in the annual statisitcs over the years.
But much more onerous than the above is the naming by the WT of the Falkland Islands as the 'Malvinas Islands' up to 1982