Well there have been numerous studies done by the Education boards over here to see what the national averages are, in order to guage whether or nto certain areas were being provided better education or not.
The tests were split into age groups as your IQ rating varies by your age more than anything else.
It was found Men had an average score of 111, compared with 104 for women.
The average IQ is supposed to be between 90 and 110, and most participants of the studies turned out to be at the upper end of this range.
An IQ of 130+ would place you in the top 3% of the populace, and IQ of 125+ in the top 10%.
The west of England statistically appeared to be the smartest region, with an average of 115, followed by the east Midlands, then the south west and finally London.
It was also found that those with the highest IQ's of all were those out of work (obviously more time on their hands for cerebral things
).
As an aside
The man with the highest IQ in the world is a Ms Marilyn vos Savant according to the Guiness Book of Records who apparently has an IQ of 228. The second highest has an IQ of 189.
So Ankh Morpork Guard, is there anything you want to tell us?