Making a curve steeper with controlled mins and maximums

Hey guys, I'm trying to make the curve steeper so the "bump" is more noticeable as shown below.

I know I can achieve this with a graph mapper but I find its not easily changeable and also hard to keep track of the minimum and maximum values. Any ideas on how i can achieve this steeper curve while keeping the minimums and maximums intact?

Attached are the image showing the goal, the rhino model, and the grasshopper file highlighting the area that I need help with.

Thanks guys!