John Rula, Fabián E. Bustamante and Moritz Steiner:

We find that cellular traffic represents 16.2% of all global traffic in December 2016. We show that the fraction of traffic traversing cellular links varies widely across countries and continents. For example, while only 16.6% of U.S. traffic is cellular, cellular composes 63% of all traffic in Indonesia and 95.9% of all traffic in Ghana.