This sub-module assumes, that you have already executed sub-module calc_volumes, i.e. the monthly volumes were calculated to one or several sets of catchment boundaries. These results will be stored in tables (one for each data type) in a linked Access database. The names are Stat_R, Stat_Q, Stat_I and Stat_E. All results are in MCM.
The statistical evaluation is done completely within MS-Access, the percentile function of MS-Excel is not used any more. Calculations are performed for dry (0.2 percentile), median and wet year (0.8 percentile) and for all four parameters (R, Q, I and E).
By selecting different reference periods, fairly different results can be produced! For this purpose, there are fields in the result-tables indicating the first and last year as well the total number of years. If the sample size is too low, there are either years not modelled or their volumes were not summarised under calc_volumes !