This appears to be about the right range. Due to the variations in how dual enrollment and other early college access are handled by states, counties and school districts, it’s hard to nail the exact number down and thus have a 99.99% estimate. But about 1 in 10 matches up with the available surveys and estimates on educational attainment.
For under-18s, girls are often slightly more likely to secure the 4 year degrees than boys, but it’s not consistently so. For 18-20yos, boys are mostly ahead compared to girls on that. Currently 15-17yos get a small but consistent chunk of early degrees, but we have yet to see them cross 100k/yr average as a group. Maybe 60k tops by now annually.
Right around 4 million BAs and higher degrees are completed each year by the under 25 crowd, and the split is around 5% to 20yos, 2-3% to 18-19yos and 1-2% to 15-17yos. I only have pure anecdotes and social media scraping to add in under-15, but they could be as high as half a percentage point to these totals, which would be 20k preteens with bachelor’s degrees. It’s impossible to say though without more technical social media deep digging, and that’s probably the ceiling anyhow.
The interesting thing is that it appears we are at or near the tipping point in which college education (including the college prep high school and junior high system) must transmute under the strain of being secured at increasingly early ages. What’s ahead?