This is wordy, instead use to find or to determine . Partly implies the concept of proportion or portion of something. Use percentage in reference to proportion of whole expressed in hundredths. Predominant is an adjective. The adverb is predominantly .
Incidence is the number in a population per unit of time.
The prevalence of rabies in skunks in 1961 was 23 per 1000 examined. There are prior and previous events, that occur before something else. Likewise there are subsequent events that occur after something else. It is often misused. The past participle of prove is proved .