I'm horribly skeptical of these statistics. I've been type watching for years and just don't see that many INTJs. Either that, or Australia is very different in composition of type than the US. The link below provides some alternative numbers.
MBTI Proximity Chart at MROB
I know it's a really bias and poor opinion . . . but even born, grown up in, and still living in Australia . . . I can even say that the statistics are questionable . . . and more so after looking at that report...