Prime-time television ratings continue to fall, with a troubling drop recorded in an important metric during the third quarter. B&C reports that the numbers in the measure that determines advertising revenues were off 8% from a year ago.

In the C3 commercial ratings for prime time in the key 18-49 demo, broadcast was down 9% and cable fell 8%. The analysis comes from Michael Nathanson of MoffettNathanson.

But the scary numbers come with a disclaimer. Nathanson is quoted in the report saying: “We continue to note that these are measured linear ratings by Nielsen and don’t account for the shift away from traditional viewing habits that are making these metrics less reliable.”

While there were a few bright spots, with AMC Networks leading the gainers among cable nets, the cable networks of Viacom, Disney, 21st Century Fox, A+E and NBCUniversal all posted double-digit drops, according to B&C.