Our World In Data claims that in 2015, 55.8% of people lived in a democracy. From OWID:
During the 19th century, most of the world’s population lived in colonial empires, autocracies, or anocracies. The late 19th century saw a limited expansion of democracies. And since that time, there has been a general upward trend in the share of the world population living under democracies, save for the period before and during World War II.
During the second half of the 20th century, colonies gained independence and more countries became democracies. Today, more than half the world’s population live in a democracy. And of those [23.23%] who still live in autocracies, four-fifths are Chinese.
This question asks how this data will look for 2040.
What fraction of the world's population will live in a democracy in 2040?
This question will resolve to the fraction of people Our World In Data considers to be living in a democracy as of 2040. If OWID no longer exists or no longer publishes a value for this question, admins may choose a credible alternative data source.