How to calculate YTD for average Values

Anonymous 

For YTD, try using time intelligence with Date calendar

Refer Example

YTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESYTD(('Date'[Date]),"12/31"))
This Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESYTD((ENDOFYEAR('Date'[Date])),"12/31"))

Last YTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESYTD(dateadd('Date'[Date],-1,Year),"12/31"))
Last YTD complete Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESYTD(ENDOFYEAR(dateadd('Date'[Date],-1,Year)),"12/31"))
Last to last YTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESYTD(dateadd('Date'[Date],-2,Year),"12/31"))

 To get the best of the time intelligence function. Make sure you have a date calendar and it has been marked as the date in model view. Also, join it with the date column of your fact/s. Refer :
https://radacad.com/creating-calendar-table-in-power-bi-using-dax-functions
https://www.archerpoint.com/blog/Posts/creating-date-table-power-bi
https://www.sqlbi.com/articles/creating-a-simple-date-table-in-dax/