In 2E, we probably had at least 50% or more as non-core PHB races, specifically Drow, Firbolg, and "Complete..." books sub-races (Forrest Gnomes, Elven subraces, etc.).
In 3E it was probably 25% or less. There was the occasional Drow (the FR version), and an occasional Kender (non standard in a FR game), but mostly core races straight from the PHB.