It is indeed interesting. Actually I'm guessing that 88% figure can be revised downwards when you consider that NSC is, by definition, a fan site - meaning that you won't be getting many casual or JCL type season ticket holders on here, who might go less often.An interesting poll.
With 48 votes so far, it suggests a turnout for an average game of about 88 per cent of season ticket holders. Which means that, for most matches, there might be about 1,500 - 2,000 seats unoccupied by season ticket holders.
A good case for ensuring a system to allow these seats to be snapped up by casual supporters.