+/* To calculate a percentile:
+
+ - Create a "struct percentile" with percentile_create().
+ - Feed in the data with order_stats_accumulate() or
+ order_stats_accumulate_idx(). The data must be in sorted order: if
+ necessary, use one of the sorting functions from sort.h to sort them.
+ - Obtain the percentile with percentile_calculate().
+ - Destroy the data structure with statistic_destroy().
+*/
+