AA does not have a 5% success rate. This misconception comes from someone misreading an old confusingly labeled graph.

AA has, according to one study, a 67% success rate. The study saw that, of people who regularly went to AA, 67% were sober 16 years later:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2220012/

Another study shows a 75% success rate, but it's behind a paywall:

https://www.ncbi.nlm.nih.gov/pubmed/10078980