By Lindsay Lowe | (staff@latinospost.com) | First Posted: Feb 12, 2013 12:14 PM EST

The Walking Dead midseason premiere broke ratings records Sunday night with 12.3 million viewers, the Associated Press reported.

Sunday's ratings beat the AMC show's previous record of 10.9 million viewers for the third season premiere in October, and it also set a series record for the highest number of adults watching in the 18-49 age group -- a 6.1 rating, to be exact, which means that 6.1 percent of Americans aged 18-49 tuned in.

Cancelled TV Shows 2013: Which one would you save? (POLL)

Why is this a big deal? Entertainment Weekly's James Hibberd explains that this kind of rating is very surprising given the stiff competition from the Grammys.

"To give you an idea of how stunning this performance is," he wrote, "ABC's Once Upon a Time sank to a series low 2.2 in the adult demo [Sunday] night and Fox's Family Guy went down to a 2.4 -- and those are the broadcast shows that performed the best against the music awards show."

Hacker broadcasts emergency alert for imminent zombie apocalypse

Hibberd added that this kind of high rating from a cable drama "is enough to cause an existential crisis" for broadcast executives, at a time when many broadcast dramas are struggling to reach even 3.0 ratings.

"When you look at numbers like this, the first thing that comes to mind is how grateful we are to the fans of this show," said AMC's president Charlier Collier in a statement provided by the Huffington Post. "They embrace The Walking Dead in a way that we wanted to believe was possible but we never take for granted."

"The cast and crew put everything they have into making this show," he added. "They're a phenomenally talented group who truly give their all. We congratulate them all."

AMC has posted a video of the full midseason premiere episode, available free for a limited time.

The Walking Dead airs Sundays on AMC at 9/8c.

© 2015 Latinos Post. All rights reserved. Do not reproduce without permission.