They can be answered by consulting a better chart! The charts show rise and fall, nothing more. That's enough info to see peaks, but we can't tell absolute any

They can be answered by consulting a better chart! The charts show rise and fall, nothing more. That's enough info to see peaks, but we can't tell absolute anything without values. Zero would have been an easy value to include, but alas. Google ngram viewer gives significantly more information. It actually gives absolute measurements, to start. What's going on with "duties"? It dropped by a factor of two. Can't get that info from the article. https://books.google.com/ngrams/graph?content=duties&year_start=1970&year_end=2022&corpus=en https://books.google.com/ngrams/graph?content=duties&year_st...