By 2020, according to marketing firm YougovтАЩs report, it spiked four-fold, nudging the 500 million mark.

Source: https://indianexpress.com/article/sports/ipl/ipl-an-integral-part-of-the-indian-summer-returns-to-take-over-our-lives-8528766/

New cities have the potential to generate 70 per cent of the country’s new jobs and GDP over the next 20 years — a process that could drive a four-fold increase in per capita incomes.

Source: https://indianexpress.com/article/opinion/columns/how-infrastructure-investments-may-be-slowing-job-creation-8908158/

These bread, that they call the “pan de selda,” were given as snacks during the jail’s four-fold advocacy information drive and feeding program that was conducted during Valentines Day, Feb. 14.

Source: https://cebudailynews.inquirer.net/489103/pan-de-selda-inmates-baked-bread-for-oprra-high-school-students