Offsetting a Set of Keys' Values Equally


I need to offset the key values of a set of rotation keys exactly 360 degrees in the Curve Editor. Is there a way to do this like the offset mode in object transforms by typing?
I can just slide them vertically, but I need it to be exact. Half a degree on certain bones spoil the floor contact quality.

For the time being, let me explain why I need this:
During mocap export of a continuous character motion, the subsequent range of keys are saved with a 360 degrees offset. for some reason I don’t know. When these subsequent ranges are attached just at the next frame where the previous range ends, the continuity of motion seems preserved but in reality the object actually rotates 360 about its certain axes in a single frame.

IF I use motion blur, that rapid rotation will eventually show up as an artifact.
When I write a value in the curve editors value box, it behaves like the absolute mode transform. and changes every rotation value to the same angle.

Is there any way to do this?