On 15 August 1971, US President Richard Nixon suspended the dollar's convertibility into gold, the cornerstone of the Bretton Woods monetary system set up in 1944. Until then, foreign central banks could exchange their dollars for gold at a fixed price of $35 an ounce. By 1973, major currencies were floating freely. Ever since, a currency's value has rested on trust in the state and its central bank, not on a metal.
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.