I have set up Google Form through which multiple people record individual items of data from vehicles. In my Responses sheet I therefore have instances where there is more than one response per vehicle registration number.
I want to add an array formula (so that it auto-calculates for all existing and future Responses) that will allow me to identify the first form result (occurrence) for each vehicle registration number, but have so far failed. In a normal sheet I would have copied down a formula such as =countif(B$1:B2,B2) where column B contains vehicle registration numbers. Where the result = 1, would be the first instance of that registration number found in column B down to that row number. Where the result >=2, this would indicate that the associated registration number had already featured previously in the range.
Having a separate count of the "1"s calculated allows me to keep a running total of the number of individual cars recorded, as opposed to the total number of data items recorded. Is there a way of doing this with an array formula so I don't have to keep manually dragging down my non-array formulae in my Form Responses sheet?
Many thanks.
