OK, let's do the math.
The first three numbers have the following possibilities:
000-772
minus
000 (1 number)
minus
666 (1 number)
minus
734-749 (16 numbers)
Therefore, the front 3 numbers have
754 possible combinations.
The second 2 numbers:
100 combinations
-
00
= 99
The final 4 numbers:
10000
-
0000
= 9999
=746,385,354 possible combinations.
746,385,354
-
987-65-4320 through to 987-65-4329 (10 numbers)
-
078-05-1120 (Check Wikipedia -
http://en.wikipedia.org/wiki/Social_security_number)
Thus, the total amount of SSNs available (to our knowledge) is:
746,385,354 - 10
=
746,385,343This does not include other possibly disallowed numbers, such as "123-45-6789", "012-34-5678" etc.NOW
Approximately 387 million of the SSNs are in use. This leaves 359,385,343 numbers still to be used. (Just under half).
There are 11,783 babies born each day in the US. Lets assume that every person grows up to get an SSN and that you don't get it until you are 18. That means that, on this average there 77,461,442 (including leap days!) people under 18 in America who will get SSNs. In 18 years there will be 281,923,901 possible SSNs left.
This means, that in 23926 days, THE USA WILL RUN OUT OF SSNS AND THE WORLD WILL GO INTO CHAOS!!
THAT'S RIGHT!
Thursday November 1st 2074 is D-Day for the world!