 Research conducted by the BBC, however, suggests that the mixed race population could already be twice the official estimate figure - up to 2 million.3.5 percent of all births in England and Wales in 2005 were mixed-ethnicity babies, with 0.9 percent being Mixed White and Black Caribbean, 0.5 percent White and Black African, 0.8 percent White and Asian, and 1.3 percent any other mixed background.In England and Wales, the 2001 census included four sub-categories of mixed ethnic combinations