Question: What was the premiere date for the series that Keith Crofford has the role of executive in charge of production?
Sentence (from "Keith Crofford"): He also serves as the executive producer of "for Williams Street" out-of-house productions such as "Sealab 2021", "Robot Chicken", "Tom Goes to the Mayor", "The Oblongs", "Minoriteam" and "Moral Orel".
Relevant evidence: No