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I'm not sure if a public one exists. If you're looking for a particular currency in a particular month let me know though (staff maintains a private one).

 

Theoretically you could use really old Sythe threads even.

Like if you were looking for Summer 2018, you could go to OSRS gold selling forum, skip to page 400 or something, and jump a bunch of pages til you find the right time period, then open a bunch of threads and take an average of the listed pricing.

I'm sure @Superfluous 's list is probably the easier route, but you know, if you want to get your "hands dirty" so-to-speak.