NEW YORK -- Katie Couric's debut Tuesday on the "CBS Evening News" brought the Tiffany Network an unaccustomed-to shade of gold, handily defeating its rivals and giving CBS its highest evening-news ratings since the 1998 Winter Olympics. "The CBS Evening News With Katie Couric" averaged a 9.1 rating/17 share in the nation's household metered markets, according to preliminary data released Wednesday by Nielsen Media Research. That was well above the 5.7/11 for ABC and the 5.3/10 for NBC on Tuesday, when both Charles Gibson and Brian Williams were in the anchor chair. It was much higher than CBS' previous metered-market average of 4.4/9 for the past four weeks. And it was the highest rating for the "CBS Evening News" since Feb. 23, 1998, during the Winter Olympics coverage from Nagano, Japan. Final ratings will be in later Wednesday.