AMC's 'The Walking Dead" is the show that keeps getting bigger and bigger each year.  Overnight ratings for the show totaled 17.3 million, the most in its history with that metrics. That's up from an already hefty 16.1 million for season four's debut.

When DVR usage three days after the fact  is included, the episode passed 22.3 million, the most ever for any non-sports cable telecast, beating "High School Musical 2."

The 18-49 numbers were even more impressive: 11 million, 2.5 million more than "Sunday Night Football." Those are demographic numbers that "American Idol" used to get in its better days but no broadcast TV ever reaches anymore. It's by far the most popular show ever on cable TV.

'The Walking Dead' is one of those increasingly rare shows today that can command a live audience not significantly cannibalized by time-shifted viewing.," said Charlie Collier, AMC president in the press release. "Who would have thought that cannibalized television could be curtailed by cannibal-ized television?" Yes, that's a joke in a press release. You don't see that too often.

No doubt AMC renewing the show for a sixth season even before the debut Sunday night was an easy call.

And AMC included social media popularity:

The premiere telecast garnered a total of 1,320,056 Tweets, making "The Walking Dead" the #1 new season drama premiere for 2014 in terms of Tweets and the #1 series premiere of 2014 in terms of Unique Authors. "The Walking Dead" is also one of the only shows in Twitter history to have had all 10 trending topics in the United States pertain to the show simultaneously. On Facebook, the day of premiere saw more than 7.7 million users driving more than 32.1 million interactions related to "The Walking Dead."

The only program last week which drew nearly as many Twitter users was "American Horror Story" with 1.1 million tweets and 6 million followers.

As for "Talking Dead," the show that comes right afterwards to talk about "Walking Dead," it drew 6.9 million viewers., its best opener ever.