Of the 195 nations in the world, how many are considered high-income?

According to the World Bank, a high-income nation is defined as a country with a gross national income capita of US $12, 236 or more in 2016 as calculated using the Atlas method. It is noted that although the terms "high income" and "first world" are often interchangeable, the technical definitions of these terms differ. As of July 2017, the World Bank has listed 78 countries (including territories) as "high income".