Average by Category quick measure - last year condition

[Zalina]

I am using Average by Category quick measure, which does exactly what I need (average of incident count by month).
However I need it to take into account only last year and not the whole dataset.
How do I adjust the DAX code of this quick measure to incorporate this condition?

Here is the DAX code from the quick measure:

Count of Number average per MonthYear =

AVERAGEX(

    KEEPFILTERS(VALUES('Calendar'[MonthYear])),

    CALCULATE(COUNTA('Created_INC'[Number]))

)

I am a newbie, so the more details the better 🙂
Thank you!

[amitchandak · Accepted solution]

@Zalina , with help from date table try like

Last YTD = CALCULATE([Avergae By Category],DATESYTD(dateadd('Date'[Date],-1,Year),"12/31"))

Last year= CALCULATE([Avergae By Category],DATESYTD(ENDOFYEAR(dateadd('Date'[Date],-1,Year)),"12/31"))

Last Year = CALCULATE([Avergae By Category],previousyear('Date'[Date],"12/31"))

[Zalina]

@amitchandak 
Thank you for your help!
The second option worked for me.
I created a new measure and here is the code I used:

Last Year = CALCULATE([Average by Category],DATESYTD(ENDOFYEAR(dateadd('Calendar'[Calendar_Date],-1,Year)),"12/31"))

It's not exactly the solution for adjusting the quick measure and having one measure for the whole thing, but this serves my purpose.
Much appreciated!
🙂