It's about telephony traffic, not data traffic from phones. Some national regulators publish the numbers every year. https://www.linkedin.com/pulse/past-point-

It's about telephony traffic, not data traffic from phones. Some national regulators publish the numbers every year. https://www.linkedin.com/pulse/past-point-peak-telephony-dean-bubley https://www.linkedin.com/pulse/past-point-peak-telephony-dea... has some discussion and links.