Sources. Chart showing the number of sterilisations reported to the central authority, the National Swedish Board of Health or the National Board of Health and Welfare, between 1935 and 1979 and the various indications for operations performed between 1941 and 1975. An unknown number of men were sterilised abroad or illegally in Sweden. This may have been the cause of the lower number of operations during the early 1970s. When, from January 1976, permission was no longer needed, the number of sterilisations grew considerably.
