> > ...The problem is that finding ariens is hard. Statistically, I'd have to know 120 people just to get 10.
> >
>
> Would you? I know that, unusually, humans are sexually active all year round, but perhaps like other mammals we have a tendency to produce our young in the spring, so that they have a summer of food to consume before the winter comes? I have no figures, but a trawl through a census might produce some...
>

Well, the US and UK census sites didn't appear to have the information, but when researching another subject (my home town's former silk industry) I came across the following figures:
Numbers of baptisms in Wokingham, Berks, 1669-1720, by month:
J-225, F-229, M-251, A-235, M-222, J-185, J-173, A-184, S-179, O-190, N-178, D-205.
Given that baptisms of the time were performed very soon after birth, this gives a fair representation of birthdates, and shows a marked tendency towards Spring births. Put graphically, it looks something like this:

||||||||||||||||||||||' J
||||||||||||||||||||||| F
||||||||||||||||||||||||| M
|||||||||||||||||||||||' A
|||||||||||||||||||||| M
||||||||||||||||||' J
|||||||||||||||||' J
||||||||||||||||||' A
|||||||||||||||||| S
||||||||||||||||||| O
|||||||||||||||||| N
||||||||||||||||||||' D

If similar conditions apply today, then to find 10 Ariens you would have to know only about 100 people, not 120.

enile