In 2023, South Korea's total fertility rate hit 0.72 children per woman, the lowest in the world. At that pace, each generation would end up about a third the size of its parents'. Explanations include housing and education costs, long working hours and the difficulty of combining a career with motherhood. The rate has edged up since, reaching 0.80 in 2025, but remains far below the replacement level of 2.1.
That's the estimate from a WHO-led study published in The Lancet in 2024, covering the half-century since the Expanded Programme on Immunization was launched in 1974. It works out to about six lives saved every minute, mostly infants. The measles vaccine alone accounts for around 60% of those lives.
According to the World Gold Council, about 216,000 tonnes of gold have been mined in all of human history. Because gold is so dense (19.3 tonnes per cubic metre), it would fit in a cube about 22 metres on each side, roughly the height of a seven-storey building. Strikingly, about two-thirds of it has been mined since 1950.