Retention rate over years in POWER BI

Question

I have the enrolment number which changes year by year, I want to calculate the retention Rate.

2017: 1137 2018:1128 2019:1002 2020:1063 2021:763

How to calculate the retention rate in this particular case.

1. A graph which shows the retention rate year over year.

Answer 1

You can use this measure:

Retention Rate = 
VAR thisYear = 
    MAX(MyTable[Year])
VAR prevYear = 
    thisYear - 1
RETURN
    DIVIDE(
        CALCULATE(
            MAX(MyTable[Enrollment Number]),
            MyTable[Year] = thisYear
        ),
        CALCULATE(
            MAX(MyTable[Enrollment Number]),
            MyTable[Year] = prevYear
        )
    )

which looks like this in a column chart: