Can anybody help with the 6'0 spitfire volumes.

i looked at a friends 6'0 20/1/2 x 2/12 spitfire and the volume on the rail and it states 34.9 litres also several websites selling the boards in the UK also state 34.9 litres, yet the firewire website states 35.3 litres and Boardshop.co.uk are stating that the pre order boards for March 2012 for the 6'0 are 35.1 litres. has the volume of the new 2012 models been increased?? Can anybody shed any light on the actual correct volume?