15%
I think people overestimate how badly football players want to keep playing, especially after retiring. It took a close personal connection and a zillion dollars to get Cutler back on the field and he had just retired.
Sure GB would be about as good of a situation as there could be for Romo to come back. But I'm sure he had plenty of good situations available this offseason too.
Lots of football players retire young when they could still play. It's a brutal game and destroys your body and mind , even for positions not in the trenches. It's not like baseball and basketball where they have to drag guys away before they embarass themselves further.