Brown World with Curly Hair

how many years before the entire world is brown (maybe light brown) with curly hair? the woman on the left is what i think the average person will look like in the future.

my guess...250 years. anyone else? put your number here and let's get an average. keep in mind the asians and their straight hair--with so many numbers, and many closed bordered countries, will be a source of brown/curly resistance. but even in china, a country only a few short years out of binding feet, it is impossible to resist rap, american black culture and the inevitable cross-racial "hookups" between round brown booties and those perfect yellow calves.