Even ABC’s new hit “The Good Doctor” could not stem the bleeding of viewers during the broadcast networks’ premiere week of the 2017-18 television season.

CBS won premiere week with an average of 9.5 million viewers for the week of Sept. 25 through Oct. 1 according to Nielsen, but the figure was down 15 percent from last year’s season opener.

A similar pattern unfolded at other networks, reflecting long-term changes in television viewing habits, analysts said. NBC, which came in second with 7.8 million viewers, was down 11 percent from a year ago. ABC, ranked third with 5.8 million viewers, down 1 percent, while Fox saw a 14 percent drop with 3.1 million viewers.

NBC was the leader in the 18 to 49 age group that advertisers covet most with 2.7 million viewers (a 16 percent decline from last season), followed by CBS (2.4 million, down 24 percent), ABC (1.7 million, even with last year), Fox (1.3 million, down 18 percent) and CW (292,000, down 10 percent).

The weekly averages for CBS and NBC were hurt by year-to-year comparisons for both prime-time NFL football games, which were down from 2016 (the CBS game on Sept. 28 was likely depressed by a 47-minute weather delay). But even with those numbers excluded, the networks had significant declines as viewers spend less time with traditional TV and consuming more video content over digital streaming devices. Streaming data for network shows are not included in Nielsen totals, although the audience measurement company is moving toward providing data that does incorporate it.

Brian Hughes, senior vice president, audience intelligence for the media buying firm Magna Global, said the downturn for premiere week isn’t surprising.

“It’s a continuation of a trend of what we saw last season,” said Hughes, who noted the numbers are within what the firm had forecast.

The number of people using television in prime time has declined steadily in prime time over the last five years with the emergence of streaming video, especially among viewers under 35 years old. Among 18 to 49 age group, prime time viewing dropped 8 percent compared to premiere week last year.

Many of the network programs gain a significant amount of audience when delayed viewing on DVR playback and video on demand services are added into the ratings totals. A majority of the deals with advertisers are based on how many people watched the commercials in the shows within the three or seven days of their initial airing. The networks are also selling more commercials on their online viewing platforms for their programs.

Despite ratings declines last season, the five major English-speaking broadcast networks sold $9.1 billion in advertising for the 2017-18 season, a 4.1 percent increase over the previous year according to the research firm Media Dynamics.

But the ratings live viewing of shows on the days they air offer a glimpse into what is clicking with the audience.

“There were actually more bright spots than we thought there would be,” Hughes said.

ABC appears to have its first big hit drama in several seasons with “The Good Doctor,” which stars Freddie Highmore as a young surgeon with autism.

“The Good Doctor,” from “House” creator David Shore, premiered with 11.4 million viewers on Sept. 25 and held that number in its second airing on Oct. 2. When delayed viewers were added, the premiere’s total gained another 5.5 million. Former “Hawaii Five-0” star Daniel Dae Kim is an executive producer on the show, which is based on a Korean drama.

CBS had a strong premiere from “Young Sheldon,” a warm comedy prequel to “The Big Bang Theory.” The 17.2 million viewers who watched on Sept. 25 were strong enough to get CBS to pick up the show a for a full season. The show moves to its regular Thursday time period on November 2.

While the original “Will & Grace” was an edgy comedy during its original run from 1998 to 2007, the new revival with the original cast intact was comfortably familiar, likely helping to draw 10.2 million viewers for its Sept. 28 premiere. Three days of delayed viewing boosted that total to 14.8 million.

“This Is Us,” NBC’s breakout family drama of last year, delivered an all time high in its second season premiere with 12. 9 million viewers on Sept. 27.

Preston Beckman, a former network executive and TV consultant, said the early successes indicate viewers are looking for uplifting entertainment.

“My gut is that people are wanting shows that make them feel good or are aspirational,” he said. “There is enough darkness in the world where you don’t have to watch it on TV right now.”

The gritty military shows and realistic crime dramas that the networks have added delivered mixed results, another sign that viewers are moving to content that is less bleak.

CBS’s “SEAL Team” with David Boreanaz as the head of a special ops forces unit, scored 9.9 million viewers in its premiere, giving the network the most watched show in the Wednesday 9 p.m. hour.

But NBC was less successful with the “The Brave,” another special ops-themed drama that opened with 6 million viewers in its first week, dropping significantly from its lead-in from the network’s top rated reality competition show “The Voice” on Oct. 2 at 9 p.m.

ABC’s “Ten Days In the Valley,” a serialized show about a kidnapped child, drew a modest 3.4 million viewers in its Oct. 1 premiere.