Also, if we are talking about a reported 8%, as in Wowhead says 8% of attempts resulted in a win condition, that is historical data, which, in no way, has any effect on future attempts. As more data is collected, that number could change, based on how many win conditions are met out of the number of attempts. If it’s 8% now, and future reports are 1% or less, we could see that number drop until it is at or near 1% itself.
Also, as shown by the Wowhead data, each person is not in this by themselves, so there will be people who get it immediately, some after a few tries, all the way up to never. The chance and probability belong to all of the attempts. Not just the one person.
“The past does not predict the future” - Ghost - Enter the Matrix