From the last number I would just say it sells as much as the other home consoles (the ones you plug on the TV).... which is not impressive for a country that used to buy them nearly as much if not more than the USA or Europe.
Maybe some new, more "japanese" titles will change this, or maybe Japanese people just lost interest in console gaming and they all want to play on their smart phones or portable devices?
Who can tell me, I won't pretend I know much about Japan, other than they used to make much more great games, now they seem few and far between :-/