The highest amount of 18 year old alive at one single moment in time

People have been having less children over the past two decades so now the amount of available 18 year olds is declining. This is happening inany countries for many reasons, usually increased prosperity retducing the need for children that will help you out

Some countries really went off a cliff (hello South Korea, are you okay? Please start accepting immigrants or you’ll cease to exist as a country) and others have it less, though still enough that it can cause severe problems. Less kids means that the gap between old and young widens twice as fast, and it means that you’ll have less work force available, and at the same time more people needing help, so the younger will have to work twice harder for the elder.