Hi, I am comparing some questionnaire responses (baseline, 3 month follow-up, 6 month follow-up). I have a full list of all entries with dates when the questionnaire was administered, but I need to identify which entries were baseline (1), 3 month follow-up (2) or 6 month follow-up (3), so that I can calculate average before and after scores. Essentially, I want to produce the 'Date sequence' column which I have highlighted. I assigned '1', '2', '3' manually, but as there are hundreds of unique IDs, I want a formula to complete the rest.

Thanks!

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