Count rows less than column value

Hi there,

I am trying to do something which should be simple, but I am getting nowhere (as per usual!)

I have a column of durations in months (integers from 0 to 120, with many repeated values) and want to count how many are less than or equal to each of the values in the 'Duration' column. Ideally, I also want to then be able to filter visuals by other columns in the table.

What is the best way to go about this? I have tried something like this in the table, which I realise is wrong:

=CALCULATE( COUNTROWS( Table ), FILTER( Table, Table[Duration] <= Table[Duration] ))

I have also tried a linked DISTINCT durations table, with a similar calculated column in that table:

=CALCULATE( COUNTROWS( Table ), FILTER( Table, Table[Duration] <= [Duration] ))

...but this does not appear to work either, and won't allow me to filter on other columns in the original table.

Any ideas?

Will