190k/1,555,200 (53-54) 12% (186k)
260k/2,217,600 (55-56) 12% (266k)

Seems close to 12% for these two examples. These were both jobs at lvl50+. Not sure what floor tier these were and if lvl<50 gives more.

Maybe it goes up based on the floor tier you are doing?

Estimation based on an exp chart. It says armoury bonus is applied to it (don't know if it was applied for these two values as given, I guess so?).