==Leftover caffeine in decaffeinated coffee == 
 I am curious about a contradiction between two sectiuons of this article: 
 * The first section mentions "the international standard of having removed 97% of the caffeine in the beans or the EU standard of having the beans 99.9% caffeine free by mass".  Accordingly, it would take between 33 and 1000 cups of decaffeinated coffee to equal the amount of caffeine in one cup of regular (unless brewing decaf somehow removes a larger percentage of the caffeine in the beans than brewing regular...) 
 * In the last section before the references, entitled "Not caffeine free", one reads "Drinking five to ten cups of decaffeinated coffee could deliver as much caffeine as one or two cups of regular coffee". 
 Anybody has an explanation for this?