1911 Census of England and Wales, General Report with Appendices, Table 122: " Proportion of Lunatic and Imbecile or Feeble-minded per Million living in each Age-Group, 1901 and 1911".

Ages. Insanity Rate per million living. Increase or Decrease per cent.
of Insanity Rate.
Total. Lunatic. Imbecile or
Feeble-minded.
Total. Lunatic. Imbecile or
Feeble-
minded.
1901. 1911. 1901. 1911. 1901. 1911.
All Ages 4,078 4,491 2,575 2,957 1,503 1,534 10.1 14.8 2.1
Under 15 629 823 26 37 603 786 30.8 42.3 30.3
15—25 2,388 2,748 632 768 1,756 1,980 15.1 21.5 12.8
25—45 5,263 5,298 3,545 3,631 1,718 1,667 0.7 2.4 -3.0
45—65 9,087 9,504 7,124 7,754 1,963 1,750 4.6 8.8 -10.9
65 and upwards 11,922 11,925 8,015 8,972 3,907 2,953 0.0 11.9 -24.4