I don't know the numbers but there are many that have apartments in NRT and many that stay at the hotel. The allowance used to be sufficient but that is not going to be the case any more come April 1. The price for the hotel will be going up at that point with no increase in the allowance. Apparently they feel that because the dollar/yen exchange rate is so good right now that we don't need an increase.
The current hotel price is 5,940 yen and will be increasing to 7,000 yen. I have been averaging just over 9 nights/month in NRT. At the current price the allowance is sufficient. At the new price it will not.