The CAA have published their Airport Stats for October 2005, which show 255 scheduled passengers to and from STN on the JFK route.
I understand EOS launched their scheduled service on 18th October 2005 with a 48-seat aircraft, which makes a total capacity of 1,344 seats on the route to and from STN over the 14 day period.
That gives an initial load factor for the first two weeks ops as 18.97% (9 passengers per flight on average).
Assuming my calculations are correct, I hope it has improved since then!
Your calculations are incorrect - I made the same mistake myself! EOS started JFK-STN on the 25th October. So in October it operated 6 out of 31 days.
That means for October, EOS carried 42.5 passengers on every flight out of a possible 48.
Also, Maxjet started ops on the 1st Nov, so October's stats only account for EOS.