I've tried searching for there're online, but I haven't been able to find any good information. Most sites assume I'm looking for they're. Wiktionary claims there're was coined by Bob Dylan, but I find this highly unlikely.
I tried Google's n-gram page for there're, but when I checked some of the early results in Google books, they didn't mean there are, many instances being mismatched by the software.
What's the earliest attested use of there're where it's intended to mean there are?