Last week (9/13-17) Jay Leno's Tonight Show adults 18-49 ratings fell well below those of Conan O'Brien's Tonight Show on a calendar week basis (2010 vs. 2009), but let's not forget that the comparable week last year was the series premiere week of The Jay Leno Show at 10pm which grabbed some big ratings.
Leno's Tonight Show for the week of September 13-17 averaged a 0.9 rating with adults 18-49 and Conan's Tonight Show ratings for the comparable calendar week last year averaged a 1.3 rating with adults 18-49.
So, last week's Leno Tonight Show ratings fell well back of Conan's Tonight Show ratings a year ago, thanks (at least in part) to…Jay?
Letterman's Late Show was in repeats and scored at a 0.6 adults 18-49 rating.
The chart shows the late night adults 18-49 weekly average ratings for 2009 and 2010.
Note: The week ending 7/2/2010, the Tonight Show was in repeats, and was delayed by Wimbledon coverage. The week of 7/9/2010 the Late Show was in repeats, and both shows Monday airings were excluded because of the holiday. For the weeks ending 7/16-8/6, Late Show was a repeat only on Friday. The week ending 8/13, Late Show was encores all week. Both Late Show and Tonight Show were repeats the week ending 8/20. For the week of 9/3/10, Late Show ratings were based on four days only. Note for the week of 9/10/10 NBC's Thursday telecasts were delayed by a primetime NFL overrun. Friday's "Late Show" was an encore, Monday results are excluded from these averages due to the Labor Day holiday. Late Show was in repeats the week of 9/17/10.