Fast National ratings for Tuesday, December 18, 2012.
 
NBC's "The Voice" enjoyed its top-rated finale to date and helped the network dominate Tuesday night among young viewers, but CBS' usual "NCIS" and "NCIS: Los Angeles" double-bill still ruled overall.
 
The other three networks barely registered at all, though The CW's "It's a Very Merry Muppet Christmas Movie" helped the network outdraw its normal Tuesday audience.
 
Among adults 18-49, NBC averaged a 4.0 rating, far ahead of CBS' 2.6 rating for Tuesday night in the key demographic. ABC's 1.4 key demo rating beat the 0.8 rating for FOX and the 0.5 key demo rating for The CW.
 
Overall, though, CBS averaged an estimated 14.85 million viewers to go with a 9.4 rating/15 share, easily topping the 7.1/11 and 12.05 million viewers for NBC for Tuesday primetime. There was the same huge drop to ABC's 2.6/4 and 4.15 million viewers, followed by another big drop to FOX's 1.2/2 and 1.92 million viewers. The CW averaged a 0.9/1 and 1.44 million viewers.
 
8 p.m. - After last week's relatively low showing, "NCIS" bounced back to 19.41 million viewers and a 3.3 rating among adults 18-49, leading the 8 p.m. hour. NBC's "The Voice" encore averaged 8.065 million viewers and a 2.4 key demo rating in second. ABC's latest airing of "A Charlie Brown Christmas" averaged 5.84 million viewers and a 1.7 key demo rating in third. FOX barely made a ripple with repeats of "Raising Hope" and "Ben & Kate" averaging 2.26 million viewers and a 0.9 key demo rating. The CW's "It's a Very Merry Muppet Christmas Movie" averaged 1.47 million viewers and a 0.5 key demo rating for the hour.
 
9 p.m. - "NCIS: Los Angeles" averaged 15.36 million viewers to keep CBS in the lead in the 9 p.m. hour, though the network slipped to second among adults 18-49 with a 2.9 rating. NBC's "The Voice" finale averaged 13.95 million viewers for second and a 4.7 key demo rating for first. ABC was a distant third with "Happy Endings" (3.18 million viewers and a 1.3 key demo) and "Don't Trust the B---- in Apartment 23" (2.55 million and a 1.1 key demo). FOX's repeats of "New Girl" and "The Mindy Project" drew only 1.605 million viewers and a 0.7 key demo rating, nearly losing to the 1.41 million viewers and 0.5 key demo rating for The CW's "It's a Very Merry Muppet Christmas Movie."
 
10 p.m. - NBC took full control of the 10 p.m. hour with 14.14 million viewers and a 5.0 rating among adults 18-49 for "The Voice." CBS' "Vegas" was second with 9.78 million viewers and a 1.6 key demo rating. On ABC, a new "Private Practice" averaged only 3.77 million viewers and a 1.2 key demo rating.
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.