In 2024, 10.2% of the world's population was aged 65 or over; from 2014 to 2024 that share rose by an average of 0.212 percentage points a year (World Bank). World Bank population data are updated once a year, so this is not a real-time figure.
Measured by the average annual rise in the share aged 65+ over 2014–2024 ("current speed", comparable across countries), the fastest-aging of the 160 countries and territories with at least 1 million people was Hong Kong SAR, China: up 0.789 percentage points a year, reaching 22.7% in 2024 (World Bank). Places under 1 million people are not ranked — a few thousand people moving can swing their share, and that is migration, not a demographic transition.
Among the 18 countries and territories of at least 1 million people where both crossings were observed, the shortest time for the share aged 65+ to go from 7% to 14% was Bosnia and Herzegovina's 15.1 years; China took 22.5 years; Japan took 24.3 years (World Bank, series 1960–2024). Another 45 countries were already above 7% in 1960, when the World Bank series begins: their span is unobserved, not a lower bound, and computing it anyway gives false results faster than China's.
China's share aged 65+ was 14.67% in 2024, rising 0.500 percentage points a year on average over 2014–2024: speed rank 11 of 160 countries and territories with at least 1 million people (World Bank). Extended in a straight line at that speed, it would reach 21% (a super-aged society) in about 12.7 years — a ruler, not a forecast: age structure is set by birth cohorts decades earlier, and a straight line distorts badly near turning points.
出处：世界银行公开数据（World Bank Open Data，CC BY 4.0），经 aging.localkin.ai 整理；数据取于 2026-10-03。