That gives us 125k high schoolers in the USA who can break 04:30 for 1600m. There are about 18M high school students. So of just the high school population alone, about 0.7% of them can do this.
Assuming there are the 4x as many adults that can do this as there are high school students, that gives us slightly less than 0.2% of the total US population capable of this.
I rest my case.