I would hardly call that "plummeting" considering the baseline https://www.eisenhowerlibrary.gov/sites/default/files/research/online-documents/salk/salk-a.pdf

I would hardly call that "plummeting" considering the baseline https://www.eisenhowerlibrary.gov/sites/default/files/research/online-documents/salk/salk-a.pdf https://www.eisenhowerlibrary.gov/sites/default/files/resear...