Define Y axis as as maximum value?

Hi Guys, 

I have a few measures displayed on my visual with the y value with total sales in numbers as you can see for example.

The three lines are percentage of the total y value. Now of course each line is seperated and starts on 0 when displayed. 

Question: I want to define my total sales (y) as maximum and display the 3 lines as percentage of y.

If i try to display lines as "Percentage of my Sum" the lines just drop on bottom. Where is my mistake?

Iam new to PowerBI so maybe sorry for a stupid question 😅

Thanks and regards,

deliser