Rating the Ratings: The first thing that must be said about any Family Guy analysis this season is that it began with one of the most inflationary single points in the era: an enormous 4.6 demo rating for the one-hour season premiere in a crossover with The Simpsons. That point singlehandedly inflates the average for the season by a whooping three tenths! Throw out the premiere this year and last year and the y2y trend instantly becomes -21%. And it was even worse than that (-24%) just taking episodes after the new year. That crossover was a big achievement, but pretty much immediately after that it became clear Family Guy was a much weaker show than it had been in many years. It got a bit of a bad break to have to air episodes against the Grammys and SNL40, but it also aired a high percentage of its fall episodes on NFL overrun nights. Overall, this was clearly not the same show that got low-2's last spring (building big on The Simpsons) when shoved to 8:30 for Cosmos. This year, it only managed around a 1.6 in the spring. Grade: C-.
Here's the now updated War of 18-49 post for Family Guy. (Also added a rough average for season three in 2001-02, since I now have a majority of the data.)