Since Leno's Tonight Show was in repeats last week, and Conan's was in original episodes during the comparable week of 2009, this week's ratings comparison is entirely apples to oranges.
In repeats for the week of August 23-27, 2010, Jay Leno’s Tonight Show averaged a 0.9 rating with adults 18-49.That's well below Conan’s Tonight Show original episode ratings for the comparable calendar week last year (August 22-28, 2009) which averaged a 1.2 rating with adults 18-49.
David Letterman's Late Show averaged a 0.8 rating with adults 18-49 for the week. Note: “Letterman’s” Friday average was excluded from the week’s average due to CBS’ NFL coverage.
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. The Tonight Show was in repeats the week ending 8/27/10.