Jay Leno’s Tonight Show continued increasing its audience lead over Late Night with David Letterman in the most recent Nielsen ratings report.

Contactmusic.com reports:

Leno averaged 4.6 million viewers for the week ended March 21 versus 3.6 million for Letterman’s Late Show and 3.3 million for ABC’s Nightline . That’s way down from his 5.2 million season average a year ago but a considerable improvement over Conan O’Brien’s average of 2.8 million from June through December.