Calculate value for every end of month for last 12 months

[Sk1X1]

Hello guys, 

I would like to calculate value for every end of month for last 12 months.

I have tasks and every task have Created date and Finished date (task can be not finished yet). It looks like this:

For one month, for example for Januar I can use this formula (it's simplified for now):

=DAYS(IF(FINISHED > EOMONTH(31.01.2018;0);31.01.2018;FINISHED);CREATED)

But I would like to do this for every month past last 12 months. Is here some way to calculate these values?

Here is simulation in my excel for January and Febuary:

At the end I would like to create AVG for every month, but that's not the main problem right now.

Thanks for every reply.

[v-chuncz-msft]

@Sk1X1,

You may add a month table, drag month to Columns of a Matrix visual, then use a measure to calculate the value and drag it to Values.

[Sk1X1]

Thanks for reply. I was able to add Month table, but I still not sure how to write measure to calculate duration time for every month.

[v-chuncz-msft]

@Sk1X1,

You may use MAX Function to get the corresponding values of rows and columns.