The Islamic calendar is lunar: its twelve months follow the phases of the Moon, so a year has only 354 or 355 days, about eleven fewer than the solar year. Ramadan, the ninth month, therefore shifts ten to eleven days earlier each year in the Gregorian calendar, cycling through all the seasons in about 33 years. Far from the equator, the daily fast from dawn to sunset is much longer in some years than in others.
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.