Audiences on the broadcast networks are getting old very quickly, according to a report in Variety that claims the median age for viewers of shows on ABC, NBC, and CBS will all tick past 50 this fall. The study — by former Magna Global EVP Steve Sternberg — found that the live median age (not counting DVR usage) for the five broadcast networks was 51, an increase of 8 years from 1999 when the median age was just 43.

For the just completed 2008-2009 TV season, here’s how the networks fared in terms of median age:

CBS: 55 (with DVR factored in: 54)

ABC: 51 (with DVR factored in: 50)

NBC: 49 (with DVR factored in: 47)

Fox: 46 (with DVR factored in: 44)

The CW: 34 (with DVR factored in: 33)

NBC’s audience is expected to age even more dramatically this coming season because of its decision to strip The Jay Leno Show every week night at 10 p.m. Leno has traditionally attracted an older audience.