The broadcast of the 2002 U.S. National Wrestling Championships, aired on ESPN2 on Sunday, June 23, set a television ratings record for a national television broadcast of the U.S. Nationals.    The rating for the show, a .30 rating, was the highest ever registered by a USA Wrestling-produced U.S. Nationals event aired on national television.    The .30 rating translated to 251,354 households that tuned in to watch the best freestyle and Greco-Roman wrestlers in the nation battle for coveted national titles this year.    The previous U.S. Nationals rating record came at the 1999 U.S. Nationals, which registered a .29 rating, reaching 185,133 households. A rating is a percent of the universe that is being measured, most commonly discussed as a percent of all television households at that time.    Only one USA Wrestling show aired on ESPN2 had a higher rating. The 1999 Freestyle World Cup, held in Spokane, Wash., scored a .39 rating.    USA Wrestling was pleased with the high rating for the U.S. Nationals, especially because the show was tape-delayed by two months, and the broadcast length was just one hour.  By contrast, this year's  ESPN2 broadcast of the NCAA Div. I Championship Finals, hosted on Sunday, March 23, in primetime at 7:30 PM, with two-hour same day coverage, had a comparable rating of .33.     "The response for this year's U.S. Nationals broadcast was outstanding, and once again shows that elite amateur wrestling is popular with America's television viewers," said Gary Abbott, Director of Special Projects. "Whenever wrestling registers a high rating for a national broadcast, it provides our sport with a strong tool to help secure additional coverage in the future."