The possible end of Michael Phelps‘ Olympic career failed to lift NBC’s primetime Olympic ratings.

Primetime coverage of the Rio Summer Olympics had a 14.2 final rating and 25.5 million viewers on NBC Saturday night, down 11% in ratings and 9% in viewership from London in 2012 (15.9, 28.0M) and down 20% and 19%, respectively, from Beijing in 2008 (17.8, 31.6M). Versus the same night of the 2014 Sochi Winter Olympics, ratings increased 48% and viewership 49% from a 9.6 and 17.1 million.

Viewership peaked at 32.7 million from 10-10:15 PM ET, as Phelps competed in his final race of the Games. On the same night in 2008, when Phelps won his single-Olympic record eighth gold medal on the final night of swimming, NBC’s viewership peaked at 39.9 million from 11-11:30 PM.

Ratings and viewership have dropped for every night of the Rio Olympics compared to four years ago, though it should be noted that London was the highest rated non-U.S. Olympics since 1994. Compared to Beijing in 2008, all nine nights have posted a decline in ratings and all-but-one has declined in viewership.

Among adults 18-49, Saturday’s telecast had a 6.8 rating — down 21% from London (8.6), down 36% from Beijing (10.6), and the lowest for the middle Saturday of a Summer Olympics since at least 1992.

Figures do not include the live streaming audience on NBCOlympics.com or cable viewership on NBCSN. Viewership on NBCSN was not immediately available, but the network scored 967,000 for its featured event of the night, Brazil/Colombia men’s soccer. With streaming and cable included, the NBC family of networks combined for a 15.0 rating and 26.8 million viewers Saturday night — still behind both London and Beijing.

NBC’s telecast was measured from 8:30-11:08 PM ET, excluding about 90 minutes of its five-hour window. It has been standard practice at NBC since at least 2000 to lop off the first half-hour of Olympic coverage by scheduling only local and in-house ads during that period (the Nielsen ‘clock’ does not start until the first national ad). It is the same on the back end of the telecast, with NBC having the option to cut off the numbers after the last national ad. The maneuvers are not frowned upon by Nielsen and are not limited to the Olympics, with NBC using the same method to cut off the first half-hour of Football Night in America.

Norfolk, VA, led all markets Saturday night with an 18.4 rating, followed by Indianapolis (18.1), Denver and Ft. Myers, FL (18.0) and Columbus (17.7). Salt Lake City, which had been the top market for each of the previous seven nights, ranked seventh (17.6). For posterity, Saturday’s telecast scored a 16.4 in the metered markets.

CORRECTION 8/16: This post originally said the Saturday telecast had 25.0 million viewers, when even in the fast-nationals it was 25.5 million.

(Sun. numbers from NBC Sports, with additional info from ShowBuzz Daily)