Well I am not entirely sure, but for starters it isn't always row 5, it could be anywhere from row 4 (say MRS) on to row 16 (e.g. GVA). At 72 there is a chance that the curtain will stay in situ through to departure, but equally a chance it will go forward or indeed back, usually one row at a time, but it can move several times each day. In the final hours this is unlikely, except perhaps FRA or GVA, since ticket sales should have largely eased off by this point.

A more typical scenario is that it may go to row 6 or 4 a day before departure and then stay there. But anything it possible.