I'm very skeptical of this. I was born and raised in Asia, and all of my peers were raised on a diet with regular milk consumption. So either we were a huge cohort of statistical outliers or that number is way, way off.
I do know that lactose intolerance rates for Asians is much higher (and consequently, less socially troublesome due to the fact that dairy is generally not a core part of cuisine), but 90% is way, way, way out there.