The Walking Dead returned for its ninth season on Sunday, but many of its former fans have apparently checked out.

The premiere episode was seen by 6.1 million viewers — down 47 percent from last fall’s season 8 return, which was seen by more than 11 million people. Among adults 18-49, the show was down 51 percent.

That’s the smallest Nielsen audience for TWD since the show’s first six-episode season back in 2010 before the series grew into a pop culture phenomenon and runaway hit.

The slide was despite pre-season buzz about the fate of Rick Grimes and Maggie Greene, as stars Andrew Lincoln and Lauren Cohan have confirmed they’re departing the show this year.

AMC points out that Sunday was particularly competitive with sports programming and they also made the season 9 premiere available on its AMC Premiere commercial-free option 24 hours before its linear airing. The move drove the single highest day of new sign-ups in the history of the service (those views are not counted by Nielsen, but also aren’t released by AMC).

Still, The Walking Dead‘s ratings peaked in season 5 (with a season premiere of more than 17 million viewers) and have ebbed each year since. This year’s drop looks particularly steep, however, and follows a lengthy time jump in the show’s storyline and an unusually conclusive-feeling season finale earlier this year that perhaps left fans on the fence feeling like this was as good as time as any to bow out.

Yet the zombie drama remains the top show on cable in adults 18-49 and is the No. 2 entertainment series on all of TV this season behind NBC’s This Is Us.