Friday, April 12, 2013 ratings — New episodes: Happy Endings, 20/20, Nikita, Undercover Boss, Vegas, Blue Bloods, Fashion Star, and Rock Center With Brian Williams. Reruns: Shark Tank, Grimm, and Kitchen Nightmares.

ABC
8pm – Happy Endings: 0.8 in the demo (-20% change) with 2.76 million.
8:30pm – Happy Endings: 0.6 in the demo (-25% change) with 2.10 million.
9pm – Shark Tank: (rerun) 1.3 in the demo with 5.11 million.
10pm – 20/20: 1.5 in the demo (-17% change) with 5.41 million.

CBS
8pm – Undercover Boss: 1.4 in the demo (-18% change) with 7.30 million.
9pm – Vegas: 0.8 in the demo (-11% change) with 7.00 million.
10pm – Blue Bloods: 1.3 in the demo (-13% change) with 10.25 million.

The CW:
8pm – Nikita: 0.4 in the demo (+33% change) with 1.32 million.
9pm – The Carrie Diaries: (rerun) 0.2 in the demo with 0.59 million.

FOX
8pm – Kitchen Nightmares: (rerun) 0.8 in the demo with 2.31 million.

NBC
8pm – Fashion Star: 0.8 in the demo (+33% change) with 2.91 million.
9pm – Grimm: (rerun) 0.7 in the demo with 2.53 million.
10pm – Rock Center with Brian Williams: 0.8 in the demo (+14% change) with 3.06 million.

These are the fast affiliate ratings. The “demo” refers to the viewers in the 18-49 demographic. The percentages represent the change since the previous original episode. (Percentages aren’t given for reruns or specials.) “Million” refers to the total number of viewers.

To see past ratings for a particular show, click the show’s link. The show pages are updated with the daily final ratings when they become available. Those pages include percentage changes in both the demo and total viewership, in addition to season averages to date.

Here are the show season averages, grouped by network: ABC | CBS | CW | FOX | NBC

What were you watching last night? Original episodes, reruns, or something even better?