HI Team Need Help on Bar chart Scalling Size .

Hi Team ,

I have used Bar chart , Showing Sales , Sales is 300 , Can i Fix Y axis values 300 constant . 

I used to Y axis Setting Start & End Values , But that is hard coded . if Sales Increases above then 300 , then thats the solutions will be not work . Apart from that if any one know any solution please let me inform .

i want to fix Y axis scalling .