Fix deform + parameter "delta"

Hi everyone, I was reading the fix deform command on lammps, and is quite clear.
nevertheless, I have a question regarding the “delta” parameter:

for instance (a extract of the code):
units metal

timestep 0.01

fix 3 all deform 1000 xy delta 4.1 units box
run 100000

Will perform a change on the tilt factor “xy” every 1000 steps up to 4.1 A at the end of the run.
I must confess that using “delta” has complicated me with the calculation of the shear rate, without knowing how to calculate it. Then, for the case of this example, what would be the global shear rate?

Thank you very much in advance

You know the amount of shearing, you know the length of the time step, and you know how many steps there will be in the run. So where exactly is the problem to compute a rate from this information?