A statistical description of the rising prevalence in the use of text-based tools for voice communications in the use of Smartphones in adolescents in the U.S..
Amanda Lenhart, “Teens, Smartphones & Texting“, Sea 19, 2012. PewInternet.org.
The statistic is composed of more than 700 individuals and is well formed. The link above is an entry point to some other items that might be interesting. Leaving aside the parentage of the entity (PewInternet.org), provide statistical data sets, although subject to its policy on access to research data.
Thank you for sharing.