Comment on "West Wing" ratings from Media Life:
"Yet the series, which this season moved to Sunday from its longtime Wednesday berth, has seen a 30 percent plunge in its ratings and now consistently finishes in fourth place among adults 18-49 in its 8 p.m. timeslot.
Some media buyers were hoping the Sunday move would invigorate the series, reversing a decline in ratings over the past several years. It's had the opposite effect, and now the sense is that the move will prove the show's final indignity. As one media buyer opined in a recent Media Life survey about the networks’ fall programs: “NBC killed a great show!
“West Wing” has long attracted an affluent audience, which, while falling in sheer numbers, remains attractive to advertisers. The show this season so far still ranks No. 1 among all series in the percentage of 18-49 viewers who have a household income of more than $75,000."
According to TV Week, this has been the evolution of "West Wing" ratings so far:
First Half: 5.6
Second Half: 5.8
First Half: 5.0
Second Half: 5.1
First Half: 5.2
Second Half: 5.3"
The Futon Critic has a general explanation about how to understand TV Ratings here.