I think last time I looked at Ngrams, the data ran out at 2010 so very pleased it now goes to 2019.
― Alba, Thursday, 15 October 2020 18:07 (three years ago) link
Hmm, not sure I trust the recent years' data. It's meant to be relative to the size of the corpus I think, but all seem to be plummeting too!
https://books.google.com/ngrams/graph?content=Glaswegians%2CEdinburgers%2CScousers%2CBrummies%2C+Geordies&year_start=1800&year_end=2019&corpus=26&smoothing=3&direct_url=t1%3B%2CGlaswegians%3B%2Cc0%3B.t1%3B%2CEdinburgers%3B%2Cc0%3B.t1%3B%2CScousers%3B%2Cc0%3B.t1%3B%2CBrummies%3B%2Cc0%3B.t1%3B%2CGeordies%3B%2Cc0
― Alba, Thursday, 15 October 2020 18:10 (three years ago) link