Even on his wiki it says this is incorrect...
Mario first appeared as "Jumpman" in 1981 game of Donkey Kong. Ok - he looked the same but had a different name so perhaps you could say that wasn't "Mario". But then he was in the 1982 arcade game Donkey Kong Jnr.. and was called Mario in that. So he's at least 26 and maybe 27. Well done Nintendo.
Oh and El Reg, his name is Mario, not Super Mario. That would be silly.