YOY - Year wise comparison

Set up a proper date table and link it to your fact table. If the month column in your fact table isn't already a full date you need to convert it to be the first day of the month, and you can control how it displays using the format string.

Once you have the date table linked to the fact table, use columns from the date table in your visuals and you can create a measure like

YoY % =
VAR CurrentValue =
    SUM ( 'Table'[Value] )
VAR LastYear =
    CALCULATE ( SUM ( 'Table'[Value] ), DATEADD ( 'Date'[Date], -12, MONTH ) )
RETURN
    DIVIDE ( CurrentValue - LastYear, LastYear )

hi Anonymous 

try to plot any visual with year column and a measure like:

YoY% = 
VAR _valuepre = 
    CALCULATE(
        SUM(TableName[Value]),
        TableName[Year] = MAX(TableName[Year])-1
    )
VAR Result =
    DIVIDE(
        SUM(TableName[Value]),
        _valuepre
    )-1

RETURN
    IF(
        _valuepre<>BLANK(),
        Result
    )

it worked like:

p.s. as suggested by joht75, in the long run, you shall be working with dedicated date tables.