Preliminary figures show Wednesday's finale of The Oprah Winfrey Show scored its highest audience in 17 years. The Nielsen Co said on Thursday that the final episode delivered a 13.3 household rating in the US' metered markets. It was the highest number since February 1994. That's when an Oprah episode called People Shed Their Disguises got a 13.4 rating. Metered market ratings measure roughly half the US and can't be translated into audience figures. A viewer count for the Oprah finale won't be available from Nielsen for two weeks. The metered market rating for Monday's surprise farewell episode of Oprah logged a 10.2. Nielsen said Tuesday's episode got a 10.7.