That's the myth that the media keeps trying to sell us: 76 percent of all "interracial couples" exist only in television commercials.
The reality: in a survey of Canadian women, more reported having fantasies about rape than about interracial sex. This general distaste for interracial relations is supported by data from dating sites, as the lowest response rate is reliably white women to black men.
It's not hard to grasp why most white women mudshark. It's for the same reason some white men prefer Asian women. They are trading on their race to obtain a mate who is higher up the attraction scale than they can obtain from their own kind.