budget table calculation

Question

Hello all
I would like to do a budget table from my sales table that has only 2 columns : budgets and month & Year.
I want to know the budget for any column i choose in the fact table, product, family, sub family or zone or any date, as long as if the sales of the year is:
Budget 2018 then multiply sales of 2018 by 1
Budget 2019 then multiply sales of 2018 by 1.2
Budget 2020 then multiply sales of 2019 by 1.3
Budget 2021 then multiply sales of 2020 by 1.4
Budget 2022 then multiply sales of 2021 by 1.5
I hope i was clear.

I came up with this but i don' t know how to go further.

Budget =
ADDCOLUMNS(
VALUES( 'Tab Dates'[Month & Year]),
"Budgets", CALCULATE( [Net Sales],'Tab Dates'[Year] = 2018) *1.2)
Maybe i would have to do with a swich (true(). I don't know.
Can you help me?
Thanks in advance all of you