Wow, that's quite some time. Do you train to syllabus as well. I'm not even sure the larger organisations over here train to that extent from 1 grade to the next.
There's a syllabus, yes - and requirements per rank. But we're a small dojo, so what you typically practice in a class doesn't have a lot to do with what's officially listed for your next rank. I don't know what the reasoning is, but I'd say the effect is that rank doesn't really mean much (i.e., doesn't tell you much about what a person can do), and people who care about rank don't stay long. I don't know whether we're better off this way or not...it's an approach, and I don't think there is a perfect one.