I am suspicious of this statistic since it is only a measure of racial purity. At some point we need to give up on this measure since it originally meant just a drop of blood is enough to be non-white. During slave days 15/16 white was still not white.

According to the Census Bureau in 2015 the US white population contracted (more white people dying than being born + immigrating) for the first time in US history outside of war (that decline continued for 2016 as well). The average non-hispanic white person is now 43 years old. The decline was slight, 0.02%, basically the opioid overdoses are the difference between expansion and contraction for white people.

Demographically, there are 198m non-hispanic whites, 59m hispanics, 47m blacks, 22m asians. The average hispanic age is 29, and the median overall age in the US is 38. The youngest state at the median is Utah at 31; the oldest is Maine at 45 (!).

Would be interesting to see birth rate/death rate by race/religion. I think over next 50+ years there will be significant shifts in demographics.