inception rate

in·cep·tion rate

the rate at which new spells of illness or cases of a condition occur in a population.
References in periodicals archive ?
5 [dollar/euro) in the last five to six years, well above its inception rate," Quaden told The Daily Star from Byblos' headquarters in Beirut's Ashrafieh neighborhood.
If under the insurance the principal outstanding at time 2m were limited to that which would be calculated using the inception rate plus the deductible, then the analogy with a put option is straightforward.