1911 Census of England and Wales, General Report with Appendices, Table 120: " Number and Proportion of the Insane at each Census from 1871-1911".

Year. Number of Insane. Proportion per million living.
Persons. Males. Females. Persons. Males. Females.
1871 69,019 32,874 36,145 3,039 2,973 3,102
1881 84,503 39,789 44,714 3,253 3,148 3,353
1891 97,383 45,392 51,991 3,358 3,230 3,478
1901 132,654 62,063 70,591 4,078 3,946 4,202
1911 161,993 76,243 85,750 4,491 4,370 4,604