I perfer <10 to <40%. (less than 10% to less than 40%) I think that 40% is at the very high end, (a pot head or alcoholic being treated as an inpatient, with follow up, at a very successful clinic.) to less than 10%, (a church group trying to restore sobriety to a crack head or worse, by having the user embrace the christ.) Good data is hard to come by, and there way are many variables, for a closer range of numbers.