Inventory Average transaction database

Hi everybody,

I'm trying to create a measure that will give me the average inventory from a transactional database. I don't have a daily snap shot of the inventory, so I have to figure this our.

I calculate the cumulative QTY with no issue with the:

Inventory Acc QTY = IF( MIN(Dates[Date]) <=CALCULATE(MAX('Inventory Transactions'[Posting Date]);ALL('Inventory Transactions')); CALCULATE( SUM('Inventory Transactions'[Quantity]);FILTER( ALL(Dates[Date]); Dates[Date]<=MAX(Dates[Date]))))

I can put this measure in a table with years and it will show the last value of the year. What I need is the average of the year.

When I try to do the yearly average on that formular I very quickly run out of memory.

Can someone point me in the right direction? Thank you!