GS-Base pivot tables can use a number of "counting" functions:

• Sum
• Sum of positive values
• Sum of negative values
• Sum of squares
• Count all
• Count negative values
• Count positive values
• Count numbers
• Count (sub)strings
• Minimum
• Maximum
• Arithmetic mean
• Geometric mean
• Harmonic mean
• 1st quartile
• Median
• 3rd quartile
• Variance - sample
• Variance - population
• Standard deviation - sample
• Standard deviation - population
• Skewness
• Kurtosis
• Most frequently occurring