According to historical reconstructions by the Maddison Project, compiled by Our World in Data, world GDP per person was about $1,100 a year in 1820 and is now above $15,000, in inflation-adjusted dollars. For millennia, average income had barely moved. The Industrial Revolution, followed by the spread of productivity gains, sent the curve soaring within two centuries.
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.