From what I've seen, the decline in Swedish education started with moving primary education from centralised state control and funding to municipal control and

From what I've seen, the decline in Swedish education started with moving primary education from centralised state control and funding to municipal control and (significantly less) funding. Then accelerated with removing national testing, removal of grading of younger kids, removal of the centralised bell curve grading, the "friskola" reform. Each change is visible in general statistics from the early exams in the university programs if you look at statistics going back to the 60s.