At least according Kotaku, almost all XBox 360 are sold out everywhere in Japan and there will not be new shipment until September. If that is true, then Xbox 360 and ToV numbers should drop to zero in next week and that would also explain why ToV did drop so dramatically.
http://kotaku.com/5039194/japan-is-totally-sold-out-of-xbox-360s-new-shippment-next-month







