Average between Years

Anonymous 
I've tryed but this option don't shows to me. 
tamerj1 
Tamer, I'm doing a caculation in each line of my database,

so I want to bring a Avg Price Unit per Year Total like the colunm MD below and this be fixed like in the Formula MD in the 1ªScreenShot ,

But when I'm seing per month in the 2ªScreenshot, I've differents prices and they shoud be the same value as the 1ªScreenShot fixed (MD)

1ªScreenshot

But We can see that each month I've different's Price Unit

2ªScreenShot

amitchandak 

The only point is that I'm using formulas to reach in my price unit, like below. 

So when I try to use Sum, it's not allowed. 

Do we have another Alternative? 

Thanks

Clever