Further to my previous post, I fell for one of the classic blunders of all time.
The first, as we know, is never get involved in a land war in asia. The second, of course, is never go up against a Sicilian when death is on the line*.
Somewhat further down the list is the blunder of not sanity checking your numbers.
Let's look at it quickly. You do the survey, the results come up, and you read "like 2% of the population..." and immediately think "wow, only 2 percent, that's not much, I must be really unique." However, in the case of this particular personality test, there are 16 possible outcomes. If the population was evenly distributed over all types, you would only have 6.25% in each type. Hmmm... So the outcome is that yes, at 2% of the population INTJs are less prevalent than other types, but not by an order of magnitude; only by 5 dB**.
*If neither of those make any sense to you, do yourself a favour: go find a copy of "The Princess Bride" starring Cary Elwes and Mandy Patinkin, and watch it over the holidays.
**dB is a logarithmic scale, 3 dB difference is double, 10 dB difference is x10, an order of magnitude. It's a microwave nerd thing.