Self-Join Redux: Counting per-record values by year

At https://www.reddit.com/r/filemaker/comments/1v7byt1/get_number_of_records_per_person_for_the_current/, a redditor asked, I use FileMaker for my patient files and am trying to find a way to display how many times that patient has come this year (1 record = 1 visit). I have a PatientID field and a TreatmentDate field. What is the best way to do this? I d like to [ ] The post Self-Join Redux:…