The Super Bowl contest between the Baltimore Ravens and the San Francisco 49ers scored the highest rating share in history for the game, based on Nielsen's top U.S. television markets, CBS Corp. said today. The game, which suffered a 35-minute delay due to a power outage, earned an average overnight household rating of 48.1 in Nielsen's metered markets, up 1 percent compared with last year's Super Bowl between the New York Giants and New England Patriots. Bluefin Labs, a firm that tracks social media activity, said that viewers produced 30.6 million social media comments, up from 12.5 million last year.