Fast National ratings for Thursday, July 8, 2010.
 
The 12th installment of "Big Brother" premiered on CBS to numbers that were nearly identical to last summer's launch. Those figures may not have been quite enough to outdraw ABC's "Wipeout," but the bump in the 8 p.m. hour helped give CBS a pair of Thursday ratings wins.
 
Among adults 18-49, CBS averaged a 1.8 rating, edging the 1.7 rating for both ABC and FOX. NBC was a distant fourth in the key demographic with a 0.9 rating, with The CW's 0.5 rating in fifth.
 
Overall, CBS averaged an estimated 7.58 million viewers to go with a 4.9 rating/9 share. The put CBS ahead of the 3.9/7 for ABC and FOX's 3.2/6. NBC's 1.4/3 was fourth, leaving The CW's 0.9/2 in fifth.
 
The ratings say that CBS won the 8 p.m. hour with a 4.4/8 for "Big Brother," which averaged 7.347 million viewers and a 2.4 demo rating (with the viewership and demo both up from last year's premiere). While ABC's "Wipeout" was second with a 4.3/8, ABC tied for first in the demo and won the hour in viewers by more than 500,000. FOX's repeat of "Glee" finished second with a 2.6/5, topping the first two episodes of NBC's three-hour "Community" marathon. The CW's repeat of "The Vampire Diaries" was fifth with a 1.0/2.
 
Overall, CBS expanded its lead at 9 p.m. with a 4.6/8 for a "CSI: Crime Scene Investigation" repeat. ABC's "Rookie Bloo" had a 3.9/7, down slightly in its third airing. FOX's "So You Think You Can Dance" was third with a 3.8/6 and won the hour in the key demo with a 2.1 rating. NBC's "Community" marathon had a 1.4/2 in its second hour, down from the first. The CW's "Moonlight" repeat was fifth.
 
A repeat of "The Mentalist" had a 5.6/10 to win the 10 p.m. hour, also claiming the hour with a 1.6 demo rating. ABC's "Boston Med" was second with a 3.4/6. NBC's "Community" marathon was down slightly in third.
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.