Approximately what percentage of the world population owns a smartphone?

36 percent of the world's population is projected to use a smartphone by 2018, up from about 10 percent in 2011.

The number of smartphone users is forcast to grow from 2.1 billion in 2016 to around 2.5 billion in 2019, with smartphone penetration rates increasing as well. over 36% of the worlds population is projected to use a smartphone by 2018, thats up from about 10% in 2011