Season 1
24 episodesAVG 8.28
Best: E24 "11:00 P.M.-12:00 A.M." (9.3)
Season 2
24 episodesAVG 8.45
Best: E15 "Day 2: 10:00 P.M.-11:00 P.M." (9.1)
Season 4
24 episodesAVG 8.34
Best: E24 "Day 4: 6:00 A.M.-7:00 A.M." (9.0)
Season 5
24 episodesAVG 8.58
Best: E1 "Day 5: 7:00 A.M.-8:00 A.M." (9.1)
Season 6
24 episodesAVG 8.05
Best: E4 "Day 6: 9:00 A.M.-10:00 A.M." (8.9)
Season 7
24 episodesAVG 8.24
Best: E12 "Day 7: 7:00 P.M.-8:00 P.M." (8.8)
Season 8
24 episodesAVG 8.20
Best: E22 "Day 8: 1:00 P.M.-2:00 P.M." (9.0)
Season 9
12 episodesAVG 8.36
Best: E12 "Day 9: 10:00 P.M.-11:00 A.M." (8.8)