Question: The Y platform, or Y body, designation has been used twice by the General Motors Corporation, the first was for a group of entry-level compacts including the conventional front-engine compacts built by GM divisions Buick, Oldsmobile and Pontiac from 1961 to which year?
Sentence (from "GM Y platform"): The Y platform, or Y body, designation has been used twice by the General Motors Corporation to describe a series of vehicles all built on the same basic body and sharing many parts and characteristics.
Relevant evidence: No