I want info on the statistics on birth dates. Specifically, about how
many people are born on each day of the year. For the whole world, or
just America. Over the last 100 years or human history or the past
year. The more info the better. You see, I am interested in Astrology
and wonder if there are more people of a particular sign, or if births
are pretty evenly spread over the calendar.

population/12=approx strength of each sign
each sign/30 = approx date of births
to some people asrology is not applicable e.g. to those who are handicap etc.

Not much on the subject, but I did find this:

From:
http://pressroom.hallmark.com/birthday_trends_stats.html
Rank   Month     Percent
1.     August    9.07
2.     July      8.80
3.     September 8.62
4.     October   8.60
5.     March     8.51
6.     May       8.30
7.     January   8.25
8.     June      8.15
9.     April     8.12
10.    December  8.07
11.    November  7.96
12.    February  7.55

Statistics for singapore
from:
http://www.singstat.gov.sg/papers/snippets/birthdays.html