Thursday, January 31, 2013 ratings — New Episodes: Do No Harm, 30 Rock, The Office, The Big Bang Theory, Two And A Half Men, Person Of Interest, Elementary, Grey’s Anatomy, Scandal, American Idol, Glee, The Vampire Diaries, and Beauty And The Beast. Episode Reruns: Shark Tank.

ABC
8pm – Shark Tank: (rerun) 1.1 in the demo with 4.59 million.
9pm – Grey’s Anatomy: 2.8 in the demo (-7% change) with 8.77 million.
10pm – Scandal: 2.7 in the demo (+4% change) with 8.10 million.

CBS
8pm – The Big Bang Theory: 5.3 in the demo (-17% change) with 17.51 million.
8:30pm – Two and a Half Men: 3.9 in the demo (-7% change) with 13.72 million.
9pm – Person of Interest: 3.2 in the demo (-3% change) with 15.62 million.
10pm – Elementary: 2.2 in the demo (-8% change) with 10.80 million.

The CW:
8pm – The Vampire Diaries: 1.3 in the demo (0% change) with 2.57 million.
9pm – Beauty and the Beast: 0.7 in the demo (0% change) with 1.73 million.

FOX
8pm – American Idol: 4.5 in the demo (-13% change) with 13.73 million.
9pm – Glee: 2.1 in the demo (-19% change) with 5.54 million.

NBC
8pm – 30 Rock: 1.9 in the demo (+36% change) with 4.80 million.
9pm – The Office: 2.1 in the demo (+5% change) with 4.44 million.
9:30pm – The Office: 1.9 in the demo (-10% change) with 4.02 million.
10pm – Do No Harm: 0.9 in the demo with 3.13 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.

What were you watching last night? The end of 30 Rock, the debut of Do No Harm, other new episodes, reruns, or something better?