Re: Graph to show growth rate

,

Based on my test, you could refer to the following steps.

1) add a new table

Table2 = 
GROUPBY (
    Table1,
    Table1[year],
    Table1[month],
    "usage", SUMX ( CURRENTGROUP (), Table1[usage] )
)

2) add a calculated column

growth rate = 
VAR Prev =
    LOOKUPVALUE (
        Table2[usage],
        Table2[Table1_year], Table2[Table1_year],
        Table2[Table1_month], Table2[Table1_month] - 1
    )
RETURN
    (
        IF ( ISBLANK ( Prev ), 0, ( Table2[usage] - Prev ) / Prev )
    )

3) format column "growth rate" as percentage