Exponential fit 1 employs the data set from 5 May to 17 May during which clusters of cases in a few high schools fuelled ...We model the expected value of the incidence of illness onset at calendar time t as E(c(t)) = kexp(r(t-??)) where k is a constant, r is the growth rate of the corresponding period, and ?? is the starting time point of exponential growth (assumed as 5 May and 29 May, respectiv