"Peak TV" was again a theme at this month's winter TCA press tour. To drive the point home, the network's research department released a list this week that revealed the average total viewer Nielsen ratings for all 1,400-plus shows on primetime television in 2015, both scripted and reality TV.

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Even though some will argue that it's all about the demographic numbers these days, and total viewers don't matter as much to advertisers, it's still unusual to see this sheer amount of ratings data in one list — particularly a comprehensive look comparing broadcast, cable and premium cable series. It certainly sheds light on why there's such a glut of TV lately. You can see the whole thing here, via the Hollywood Reporter, but here are six facts learned from the list:

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(Note: These numbers only represent Live+7 data from Nielsen, which accounts for live viewing, plus who watched a show for up to a week after it first aired. This does not account for streaming or on-demand.)

1) Despite losing some high-profile shows, AMC ruled at basic cable ratings last year.

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"Mad Men" and "Breaking Bad" are gone, but how would AMC even notice? "The Walking Dead" (19.4 million) is the third-most watched show on all of television. The next-highest cable show? Spin-off "Fear the Walking Dead" (11.8 million), which ranks No. 24. "Game of Thrones" (9.5 million) is the first non-AMC cable show at No. 48, followed by none other than TNT's unstoppable "Rizzoli & Isles" (6.5 million) at No. 90. And even then, AMC's "Better Call Saul" and "Talking Dead" aren't far behind.

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2) HBO and Showtime, revealed.

It's not always easy to find ratings data on the premium cable networks, but here you go. "Game of Thrones," "True Detective" (4 million) and "Ballers" (2.7 million) were the three highest-ranked shows on HBO last year. The three least-watched were "Looking" (343,000); "The Casual Vacancy" (315,000); and "Doll & Em" (which didn't reach Nielsen's minimum reporting standard).

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On Showtime, the top three shows were "Homeland" (2.6 million); "Shameless" (2.5 million); and "Ray Donovan" (2.3 million). The three lowest were "House of Lies" (995,000), "Episodes" (661,000) and "Happyish" (382,000).

And as a reminder, these numbers don't account for various services like on-demand, along with network-specific viewing like HBO Go and Showtime Anytime. With all of those taken into account, HBO reports more viewership for shows like "Game of Thrones" (20 million); "True Detective" (11 million) and "Looking" (1.8 million).

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3) The least-watched shows.

There are tons of shows that don't even have enough viewers to meet the minimum requirements to be measured by Nielsen. According to FX, the least-watched primetime show on TV is "Celebrity Conversations" on Ovation, which ranked at the bottom of the list — the show features film critic David Poland talking with stars from Judd Apatow to Tobey Maguire. The last show on the list that reached the minimum reporting standard? Discovery Life's "NY ER" (149,000), which chronicles what happens in real-life emergency rooms, ranked No. 1356.

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And if you're curious, FX reports that the least-watched broadcast show in 2015 was CW's "Dates" (553,000), a comedy about online dating, imported from the U.K. and aired last summer.

4) The least-watched channels.

Despite the massive amounts of competition, some of the lowest-rated channels still continue to crank out programming. Many channels have multiple shows that ranked too low to be rated by Nielsen, including the Cooking Channel ("Southern Fried Road Trip," "Unique Sweets"); male-centric Esquire ("Brew Dogs," "Knife Fight") and FYI Network (fashion reality shows "Get Swank'd," "Style Unzipped") — which all had big rebrandings in the last five years.

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5) The most-watched reality shows may not be what you think.

The most-watched primetime reality show? "Dancing With the Stars" (14.5 million), the No. 7 show on TV. And although the show doesn't get the same amount of buzz, NBC brings some stiff competition with "The Voice" (14 million), followed by "America's Got Talent" Tuesdays (12.7 million) and Wednesdays (10.7 million). Meanwhile, CBS's Survivor" (11.6 million) shows up at No. 25; Fox's "American Idol" (11.5 million) results episodes are at No. 28, and performance nights (10.5 million) are No. 40; and ABC has "The Bachelor" (9.6 million) at No. 47.

Meanwhile, in cable reality land — which falls under the "docu-series" category — Discovery wins the race with "Gold Rush" (5.7 million) and "Alaskan Bush People" (4.8 million).

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6) The most "social" shows don't necessarily have the highest ratings.

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One way shows can break through the TV clutter is landing on Nielsen's "most social" list. The ratings company revealed the top 10 most-tweeted shows last year, and they don't necessarily match the shows with the most viewers. Some do, like "The Walking Dead," which was the most-tweeted show, plus the hugely-rated "Empire" and "Game of Thrones." Plus, ones you would expect, like "The Bachelor," "The Bachelorette" and ABC's Shonda Rhimes shows "Grey's Anatomy" and "Scandal."

However, lesser-watched series like ABC Family's "Pretty Little Liars" (3 million) and NBC's "Parks and Recreation" (4.6 million) also made the Top 10 of TV Twitter — which maybe helps explain why "Parks and Rec" stuck around for so long.

*This story has been updated to reflect that these numbers are live +7 ratings, along with a note about pay-cable programming.