The popular question words how, when, what, why, which and some more all have their accompanying word ending in -ever, like however and whatever. It seems to me that the word wherever is somewhat
Whoever else Whatever else Whenever else Wherever else Why ever else (Note: Whyever used to be an accepted spelling, but it has mostly died off.) However else In your example sentence, it would work fine with a slight reordering: Fertility might have fallen among women born between 1940 and 1960, and whenever else remained unchanged.
Both footnotes and endnotes require that a superscript number be placed wherever documentation is necessary. The number should be as near as possible to whatever it refers to, following the punctuation (such as quotation marks, a comma, or a period) that appears at the end of the direct or indirect quotation.
In the cited context, wherever is an "emphatic" alternative to where. But a "stylistic choice" like that is unusual in the context of legal texts, so at least some readers will try to come up with a reason for the unusual choice. Personally, if I saw wherever in this context, my first guess would be that it's from a fake news source trying to promote a non-existent law.
Do the words 'Where' and 'Wherever' mean the same in this sentence?
orthography - Why is it "wherever" instead of "whereever"? - English ...
Apologies for the title which sounds like the Shakira classic, but would you say "Thank you for providing help whenever possible" or "wherever possible"
None is ungrammatical; few would use the unabbreviated forms; 'whenever' and especially 'wherever' would probably be a lot more idiomatic. The variants starting 'wherever' etc would probably be more usually used.