PROC HPBIN computes the 0% (minimum), 1%, 5%, 10%, 25%, 50%, 75%, 90%, 95%, 99%, and 100% (maximum) percentiles of each binning
variable.

Let m be the number of nonmissing values for a variable, and let , , …, represent the ordered values of the variable. Let the tth percentile be y, set , and let = j + g, where j is the integer part of and g is the fractional part of . Then the tth percentile is described as:

Note: To avoid the time-consuming sorting process, the HPBIN procedure uses an iterative projection method to compute percentiles
according to the preceding formula.