What the British have to do with it?
They were probably referring to a survey done by Engineering and Technology magazine, where one of the outcomes was that about 25% of the British believe that we never landed on the moon http://edition.cnn.com/2009/TECH/space/07/17/moon.landing.hoax/index.html
If they said 35% then they're probably refering to this survey perfomed by I don't know who, using unknown questions in an unknown structure commissioned to promote the x files movie.
http://www.guardian.co.uk/uk/2008/jul/31/1
That's how the best science is done.

