IPv6 connectivity steadily grows but by 2019  still will account for only 1/3 of total global Internet traffic.     

Cisco’s Visual Networking Index Report predicts that 41% of all fixed and mobile networked devices will be IPv6 capable in 2019, up from 22% in 2014, and IPv6 traffic will account for 34% of total Internet traffic globally, up from 6% at the end of 2014.  Read More.