Every November, more than half a million candidates sit the 'suneung', South Korea's national university entrance exam. During the English listening test, about 35 minutes long, no plane may take off or land anywhere in the country, so as not to disturb the candidates. In 2025, around 140 flights were rescheduled as a result. On exam day, the stock market and many offices open later to keep the roads clear.
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.