As 2018 comes to a close, 51.2 percent of the global population (3.9 billion people) will be on the internet, according to the International Telecommunications Union (ITU), with Africa contributing the strongest growth of internet usage. In 2005, 2.1 percent of the African population was online, with that figure jumping to 24.4 percent in 2018.
The ITU is a specialized agency of the United Nations (UN), responsible for matters involving information and communication technologies. Within its three sectors—radio communications, standardization, and development—the agency aims to “allocate global radio spectrum and satellite orbits, develop the technical standards that ensure networks and technologies seamlessly interconnect, and strive to improve access to ICTs to underserved communities worldwide,” according to ITU.
You can see the growth pattern of internet usage in the Statista chart below.