Excel Sheet improvement needed

Hello all,

I would like to improve as follow the attached excel:

At this time, revenues (Expected monthly income/car) are entered once in the data sheet INPUT and remain constant throughout the vehicle's lifetime.

I would now like introduce profit margin based on car's age in order to get Expected monthly margin/car.

To do this, I want to:
1. On a new sheet "Profit marging", create again a simulator, but this time considering the value of the "profit margin" parameter which define the expected monthly margin/car based on car's age
2. Introduce a "profit margin" parameter which is a percentage of revenue (Expected monthly income/car) and depends on the age of the vehicle.
3. The value (%) of the "profit margin" parameter must be definable as a function of the age (in months) of the considered vehicle.
4. The age ranges to be considered and the "profit margin" parameter values within each age range are defined in the INPUT tab. i.e. 90% by age <=12months, 80% by age >12months by <=24months, 70% by age >36months up to age 72 months
5. The "profit margin" parameter value remains valid within each age interval and beyond if no other age interval is defined.

In the attached file, the yellow cells are samples to show a bit what I mean.

Please let me know you thought on this update.

Regards,

Joel