What would be your own first try?
Please come up with a workbook
for others to see and help.
BTW, the following Table Calculation
would give the result you want:
RUNNING_MAX( MIN[Delinquency Bkt] )
Compute using --> [Month]
And the [Month] should be a (correct) Date type.
If not (and it is a String), the calculation is needed
to convert [Month] from the String to Date type.