Sexual orientation
In 1896, Berlin sexologist Magnus Hirschfeld makes a system that measures the strength of sexual desire of an individual. This system measures on two different scales of 10 points. The scales are A (homosexual) and B (heterosexual). A heterosexual individual may be A0, B5. A homosexual individual may be A5, B0. An asexual is A0, B0. Someone with a strong attraction to both genders may be A9, B9.