Computing Percentiles in SPSS using the Frequencies, Explore, and Compute Variable Methods

This video demonstrates how to compute percentiles in SPSS. The Frequencies, Explore, and Compute Variable methods are reviewed.

[@covariance5446]

Hello,
Can you explain briefly why you include the "-.5" term in the numerator?
Intuitively, I expected that the calculation of percentile scores as a function of rank scores would be:
P(R) = R/N*100
where N is the number of cases. What is the purpose of subtracting .5?