Britain's TV stations will see their male viewing figures decline as the ratings are adjusted to match new demographic data.

BARB (Broadcasters' Audience Research Board) is reconfiguring its TV audience 'universes' to take into account statistics from the 2001 UK census.

One of the biggest effects will be a drop in the young male ratings to reflect the decline in this demographic. Broadcasters across the board will see a 9% decline in reported commercial impacts (the audience for TV ads) among 24 to 25-year-old men.

"The 2001 census shows that there are fewer younger men in the population as a whole, so the proportions change," explained BARB head of research Tony Wearn. "It’s our chance to draw the line again."

Other age groups will also be affected. Commercial impacts for males aged 35-44 will be down 6.2%.

Data sourced from: Media Week (UK); additional content by WARC staff