Question: When was the Rob Renzetti the supervising producer for Gravity Falls?
Sentence (from "Rob Renzetti"): Robert Renzetti (born September 12, 1967) is an American animator and director who created the animated television series "My Life as a Teenage Robot" for Nickelodeon, and directed "Dexter's Laboratory", "The Powerpuff Girls", and "Samurai Jack" for Cartoon Network.
Relevant evidence: No