Isn't the puffs per ml dependent upon the size of puff you take, whether you are dripping or using an atomizer/cartomizer, what your ohm rating is, and what volts your system is using. Sure seems like hotter and or higher volt systems would use more juice and someone taking large hits would use more than someone taking short puffs.
I smoked an analog in less than 45 secs since I hotboxed and only got about 9 - 11 draws tops on one...