Ohio lags behind the national average and at least half the states in people holding science and engineering degrees, according to data released this week by the U.S. Census Bureau.

About 31 percent of the 1.9 million Ohioans 25 and older with bachelor’s degrees said they had a degree with a major in fields that qualify as science and engineering on a new question asked in 2009 by the bureau’s American Community Survey.

The national percentage is 34.9 percent. Ohio also is behind the national average in the number of adults with college degrees.

The numbers are troubling for those who see an educated work force as essential to improving the state’s economy. “The whole secret to economic growth is human capital,” said Tom Lasley, executive director of EDvention, a local advocate for the study of science, technology, engineering and math, or STEM. “Educated people have more potential to generate income.”

President Obama has made it a national priority for 60 percent of U.S. citizens to hold advanced degrees by 2020 in order to remain competitive with the rest of the developed world.