Over the past century, the number of Catholics around the globe has more than tripled, from an estimated 291 million in 1910 to nearly 1.1 billion as of 2010, according to a comprehensive demographic study by the Pew Research Center.
But over the same period, the world’s overall population also has risen rapidly. As a result, Catholics have made up a remarkably stable share of all people on Earth. In 1910, Catholics comprised about half (48%) of all Christians and 17% of the world’s total population, according to historical estimates from the World Christian Database. A century later, the Pew Research study found, Catholics still comprise about half (50%) of Christians worldwide and 16% of the total global population.