I am new to the technicalities of the bicycle so please excuse what might appear to be a dumb question ! I understand that the first two numbers on my Rotrax 'Concours' steerer - 52061 - refers to the year (1952) but am puzzled about the '62'. Does that refer to the number of frames built of that model by the company or simply refer to the number of frames -irrespective of model - built by the company to date in that year ? I'll certainly appreciate the answer to this. Fraser