IDIOCY AT VARIOUS AGES, 1891.
Under 15 years 1 person in every 4,679 was an idiot
15 to 20 years 1 person in every 2,725 was an idiot
20 to 40 years 1 person in every 3,213 was an idiot
40 to 60 years 1 person in every 3,152 was an idiot
60 and upwards years 1 person in every 1,360 was an idiot