This is none of the government’s business except that it recognizes the sexually based discrimination and works to end it. The fact that not everyone is heterosexual should be enough ensure the rights of everyone in order to end sexually based discrimination. We do not need to know how much a minority non-heteros are, just that they exist and are oppressed. As for gender, the census currently requires people to identify themselves or are identified by the census taker by observation only as male or female. Trans and others now choose either of those limited classifications. Maybe add “unspecified” if someone does not want to answer, is in transition, or is gender neutral.