Question: The 2011 USA Sevens competition was held at a football stadium with an elevation how many feet above sea level?
Sentence (from "2007 USA Sevens"): The 2007 Steinlager USA Sevens was a rugby union sevens tournament held on February 10 and February 11, 2007 in the United States at 44,500 capacity Petco Park in San Diego, California.
Relevant evidence: No