I had a quick question regarding a significant change I noticed from the 2014-2019 VNI report to the latest 2015-2020 report. For the U.S. market, average per device monthly usage numbers seem to have all come down.

For example, the 2014 report forecast the average smartphone to use 1,801 MB per month in 2014 (vs. 1,214 MB per month in 2013), but the 2015 report uses a 2014 number of 1,061 MB per month growing to 1,433 MB per month in 2015. Said another way, the 2015 smartphone usage number from the latest report (1,433 MB per month) is lower than the 2014 usage number (1,801 MB) from the 2014 report. Was there any change in methodology that explains this (I realize phablets were added to the smartphone category in 2015, but wouldn't have expected this to drive the change). I also notice the same challenge across other device categories e.g. tablets, PCs etc.

Thanks much – any insights would be very helpful.