start here: Average amount of CBD extract from 1 pound?
Because “THC” is not a required part of your query.
did you try searching “distillate yield” ie Search results for 'distillate yield' - Future4200
because the answer looks to be right the fuck there…
even the all knowing one yields on that query, although you have to look at the second page of results.
what DID you use as a search query?
No seriously; they don’t seem to teach this skill in school…
…why would you throw your good weed at distillate?
see: hot dog water
Edit:
Looking for love in all the wrong places?
How about https://scholar.google.com/scholar?q=thc+distillate+yield
Just in case by “accurate” you meant “published” or “peer reviewed”.