I spent 11 months as a blue belt. I also trained 6 days a week and twice a day on Tuesdays and Thrusdays. Aside from that I also competed several times and did well. It's all a matter of how your professor feels you are progressing and whether he/she feels your ready for the next step.
The whole "10 year minimum" to get your black belt is a ridiculous concept to me.
that is some serious mileage.