Formula concatenate data in multiple rows based on match data in a different row.

I am trying to create a formula that will identify all matching data in column A, where there is a match the data in column D should be returned in column E with each result seperated by " / ".

I have uploaded a spreadsheet with a sample of the ideal outcome. Where the ID in column A matches, the data in column D should be returned for all matches in column E with " / " as the seperator.

I have tried the formula =INDEX($D$2:$D$17,MATCH(A2,$A$2:$A$17,0)) but this only provides one match.