WCA descriptors ref 9 re bladder voiding

Could anyone explain the logic behind fewer points   being awarded if the voiding of the   bladder is more frequent ie 15 points re Descriptor C(a) once a month and C (b) the majority of the time 6 points?

Thanks in advance

Higher descriptor is about actual loss of control whilst lower is about risk of losing control?

However, expecting to find logical answers to many of these questions isn’t always a good idea…..

The wording   seems to be remarkably similar ie the same words are   used

Risk = possibility, exposure or threat.

The majority of the time is at risk of ...... if not able to reach a toilet quickly.

At least once a month experiences:

Experiences = practical contact, event, occurrence, undergo’s.