The value of DIFFS may depend somewhat on the value of TOL
chosen, as the approximation chosen to calculate DIFFS depends
on both the number of entries and on the size of TOL
(how accurately DIFFS must be calcuated).
The S option sometimes returns a confidence level of 1.0 in the small
statistics calculation, i.e. there is no probability that the two numbers
came from different distributions.
This is due to finite precision.
Values slightly higher than 1.0 will be returned when the two content
values are identical, since no statistical test could claim they came from
different distributions.