[inotherwords]

Your speedometer arrow motor still has 7153 steps to max position (physically). Those steps points reflect how many steps the motor has to pass to get to the corresponding point. For example, when you drive at real 116 km/h (120 km/h as displaying speed), the speedometer arrow should be at point #4 and arrow's motor should pass specified number of steps at steps point #4.

So you need to calculate middle step points (between 0 and 7153) accordingly to your speed points.
For example, point #4 again:

116.0 km/h of 250 km/h (point #5) means 116/250 = 0.464. Multiply it to maximum amount of steps (7153) and you will get amount of steps to get to point #4. 3319 steps in this case.

So try to calculate points #2 and #3 by yourself using the same method. BTW be aware that it works only if your dial is marked linearly (with equal speed steps).