>>507940677 (OP)Well first of all it will already be down below 80% most likely, but anyway it shouldn't be more than 5% browns in a country like England. China is more than 90% Han, the vast majority of the rest is different ethnic groups who have been there for centuries, most of them barely discernible from Han anyway. Not only that, but the far out niqqas like the Uyghurs typically didn't have family planning policies applied to them (as in the 'one child policy'), so they were allowed to breed much faster.
The only way shit like this happens is a concentrated effort at demographic replacement.