incidence

in medicinal chemistry
https://doi.org/10.1351/goldbook.IT06828
Number of occurrences of illness commencing, or of persons falling ill, during a given period in a specific population: usually expressed as a rate.
Source:
PAC, 2004, 76, 1033. (Glossary of terms used in toxicokinetics (IUPAC Recommendations 2003)) on page 1054 [Terms] [Paper]