In 1933-34, the Belgians conducted a census in order to issue 'ethnic' identity cards, which labelled every Rwandan as either Hutu (85%) of Tutsi (14%) or Twa (1%). The identity cards made it virtually impossible for Hutus to become Tutsis, and permitted the Belgians to perfect the administration of an apartheid system rooted in the myth of Tutsi superiority... Whatever Hutu and Tutsi identity may have stood for in the pre-colonial state no longer mattered; the Belgians had made 'ethnicity' the defining feature of Rwandan existence.