NEW YORK (AP) — NBC says an estimated 17 million people in the United States saw the opening of the Tokyo Olympics on Friday. That's a 36% decrease from the kickoff to the Rio de Janeiro Games five years ago. That figure includes people who watched the ceremony live in the morning U.S. time and those who saw an edited version in prime time. That's also less than half of the 40.7 million who saw the ceremony for the London Games in 2012. It's difficult to judge how much the decline is due to a lack of interest in the Olympics or if the changes in how people watch television have hurt TV ratings in general.