How deep the bench of legacy D&D players?: Seed of Worlds (opens in new tab)

Troy Press published a piece "D&D Rules, According to Past Players" based on a survey they did - and I am fascinated by the 'mentioned in passing' implication of a huge amount of non-active D&D players in the USA - something like 1 in 6 USA folk have played D&D at some point, apparently. Does this m