those that espouse to the idea that usage has shrunk in this age group are not taking into consideration that the 13 - 17 year olds from 2011 are now 3 years older and those 15, 16 and 17 year olds are now in the 18, 19 and 20 year old group now ... it is not like they have disappeared ... also, if I am not mistaken, the new group of 13 - 17 year olds in 2014 have a less population % than those from the same group 3 years ago ...