They must have different hours requirements at Hombu then. I'm not sure that you could meet the Aikikai requirement for hours for sandan in ten years of you trained every single day.
but you'd have to progress pretty well/fast; the minimum time would be just under 7 years for Yondan.
If you start when you're fifteen and trained almost every day for the first year then for bring total days up to just over 1315 days over 7 years you could meet minimum requirements by the age of 22...
Minimum requirements; I'd be surprised if this was anywhere near the norm though...