If you see the A-class than there is also a possiblity for tapered masts in the calculations as it was in the early days when they still had the alu masts. Most of these where tapered, specially the 10 mtr long one's. When they changed to around 9 mtr's the tapering dissapered and also with the coming of the carbon masts.
In the measurement form of the F16 there is also the possiblity for tapered masts.