https://www.recode.net/2018/2/26/17044010/pyeongchang-winter-olympics-2018-ratings-sochi-russia-watched

On average, 19.8 million people watched watched NBC’s* primetime coverage of the Winter Olympics in PyeongChang this year — 7 percent fewer than the previous winter games in Sochi.

Only two days of the entire 18-day PyeongChang 2018 Winter Olympics were more popular than Sochi: The second Tuesday (women’s alpine skiing) and the final Saturday (figure skating gala).