90 day rolling calculation

[jgreen95]

i have a list of Checks that either get a pass or fail(1/0), all of these have a week ending date attached .

How would i produce a 90 day rolling average table, so for each week ending date i have what the average pass rate was over the last 90 days?

they need to be split by a dimension as well if possible. Table table looks like below: 

Type	Region	Outcome	Week
Sample	East	1	15/03/20
Sample	East	0	08/03/20
Routine	North	1	08/03/20
Third Party	South	1	08/03/20
Sample	West	1	01/03/20