What is the chance of paralysis on an enchanted weapon?

According to UESP, the chance of paralysis on a weapon enchanted with Paralysis effect is 25%.

I have confirmed the 25% number with empirical testing.

Test Data:

Number of Hits between Paralysis:

Giant: 3 11 12 8 1 1 2 4 2 1 5 4 3 3 1 1 4 7 5 9 7 10 2 9 1 6 1 4 10 3 1 1 3 1 2 2 4 2 1

Average: 4.02

Count: 39

Implied chance of paralysis: 24.9%

Bandit Marauder: 1 4 1 1 14 1 2 6 7 10 5 1 3 15 6 8 4 1 1 1 7 16 1 3 1 1 9 1 2

Average: 4.59

Count: 29

Implied chance of paralysis: 21.8%

Total Average: 4.26

Count: 68

Implied chance of paralysis: 23.4%

(Close enough for the small sample size, I say.)

Source: UESP Weapon Effects