Results of the Augmented Dickey-Fuller test of the transformed, seasonally differenced time series for all four diseases.

†Log-transformed and seasonally differenced monthly incidence /100000 population.**Significant at the 0.01 level.‡is the computed ADF test statistic which is compared to the critical values at significant levels α = 0.01, 0.05 and 0.1. If the test statistic is less than the critical value, then the null hypothesis is rejected, and thus the variable is stationary.