I would like to point out that any statistics coming from AA must necessarily be nonsence. There is no way to collect accurate data from an anonymous population.
I would further point out that success rate itself is a nebulous concept. Is it abstinance for 90 days, a year, 10 years, or forever. For cancer treatment, organ transplant, etc., statistics are always stated as a number of years of continued health/life.
Stories abound in AA meetings of people with 10, 30, 30, 40, or more years of sobriety that "went back out" and died from the disease. Were they successful? The only meaningful measure is forever, which also cannot be measured, at least not without extreme difficulty.