More than a third of U.S. adults, or 33.4 percent, had a bachelor's degree or higher in 2016, the U.S. Census Bureau reported Thursday. That's the highest level of educational attainment since the Bureau began collecting those statistics in 1940. At that time, only 4.6 percent of all adults had college degrees.

A decade earlier, in 2006, 28 percent had bachelor's degrees. Bachelor's degrees are more likely to be held by Asians and whites, and less likely for African-American and Hispanic populations.

High school graduation rates also improved, with 89.1 percent completing high school in 2016, up from 85.5 percent in 2006.

Each degree increased average annual 2016 earnings: $35,616 for someone with a high school degree, $65,482 for someone with a bachelor's degree, and $92,482 for those with advanced degrees. Men with bachelor's degrees earned considerably more than women with the same degree — $79,927 compared to $50,856, the Census reported.

In hiring college graduates, employers choosing between two candidates with equal experience, choose based on major, a leadership position, involvement in extracurricular activities, and high grade-point average, the National Association of Colleges and Employers reported on Thursday. Of those, major was key, just slightly edging out evidence of leadership ability.

Those four attributes were more influential than the school attended, fluency in a foreign language, volunteer work, or study abroad, NACE said, reporting on its annual survey of employers.