Performance Improve for Measure

[Companyuser101]

Hello together, 

I need to improve the performance for my measure. 

So in my data we have 6 different manager. All the manager have different costumers. 

Every costumer has goals to achieve. When they achieve the goals, we pay them a bonus. 

The goals are for example retails.

So all the manager have the sum of the costumers goals. For example

costumer 1: achieved 3 from 6 retails --> 50%

costumer 2: 4 from 10 --> 25%

costumer 3: 2 from 2 --> 100%

Then the manager has then achieved: 9 from 18 --> 50% 

But when we take the average from the three costumers we have: 41,67% 

And I want the average, but Power BI gives me the 50%. 

So when I calculated the bonus I then made a sum of every bonus from the costumer and got this:

so for every bonus I filtered after the costumer, which gives me a long measure and takes a lot of time to process.

When I do this I get the right bonus. 

I tried to make it slimer: 

Here I filtered after the manager, but It does not work because I get the 50% (from above) 

How Can I change the measure to improve performance?

Thank you!