Fix endurance

This particular EHM engine drops the endurance rating for older players significantly -- for instance:

Andrew Shaw RW 33 5750000 2 87 70 80 76 79 78 81 79 36 65 80 76 79 75 79 74
Stefan Noesen LW 31 5750000 4 79 76 74 78 78 78 76 78 62 74 99 69 78 76 77 77
Sean Couturier C 31 8000000 4 68 78 76 81 83 80 81 85 56 80 87 80 80 78 81 79

Jonathan Toews C 36 6750000 1 41 80 75 82 83 83 74 83 57 74 85 88 82 79 80 79

Claude Giroux C 36 7500000 1 24 80 82 82 75 76 65 82 49 77 88 80 76 81 72 76

I checked other teams and this seems to be an issue league wide:
Chris Kreider LW 33 6000000 3 65 80 78 79 80 77 76 85 52 69 82 65 79 79 77 75
Milan Lucic LW 36 3000000 1 70 76 74 76 83 80 80 73 62 70 71 67 84 75 81 75
Logan Couture C 35 5000000 1 38 81 78 85 74 83 67 81 62 88 75 77 82 81 74 78

If anything I would expect older players to slow down, but not necessarily lose endurance. Could we do a one-time/ongoing fix for this?