Gruff - using customized scale

Hi I searched through the forum for the answer but couldn’t find any
pointers. I have created an application using the gruff graphs. The
problem is that these charts automatically calculates the y-axis scale.
The requirement is to be in multiple of 100’s but internally it by
default calculates something else which is not very convenient to read.
Can someone please post some examples for the same or any alternative
way to make/define the interval of the scale?