Despite a 5% decline in headcount this year, independent workers remain a powerful economic force, according to a report from MBO Partners. And independents generate more than $1.1 trillion in annual income, equal to more than 6% of US GDP.

Over the next five years, according to the 2016 State of Independence in America report, the number of full-time and part-time independents in America will grow by 16.4% to 34.1 million in 2021, to comprise 29% of the private, non-farm workforce.

The total number of self-employed workers aged 21 and over in 2016 remained close to the 2015 total at nearly 40 million. This includes 16.9 million full-time independents (15+ hours/week), 12.4 million part-time independents (under 15 hours/week), and 10.5 million workers who qualify as occasional independents, those who lack an “average” independent workweek.

Nearly half of full-time Independent workers, 47%, report making more money working on their own than they would in traditional employment, and the average gross income generated from independent work has risen 30% since 2011; 3 million independent workers earn more than $100,000 per year. More than four in 10 have four-year college degrees or higher, including 20% with advanced degrees, and this distinction is even higher among independents’ large Millennial population, where nearly six in ten workers have four-year or advanced degrees. Independent workers are experienced – averaging 10.5 years’ experience – and generally command high salaries, with 28% of the full-time independent population earning more than $75,000, according to the report.

“Over 40% of the U.S. adult workforce works or has worked as an Independent at some point in their lives,” said Gene Zaino, MBO Partners founder and CEO. “The independent workforce is a critical entrepreneurial force in America. Even in the midst of a rebounding job market and economy, independence remains a viable and desired career path.”

MBO expects that by 2021, almost half of the private workforce, 48%, will have spent time as independent workers at some point in their work lives.

MBO Partners provides back-office services for independent consultants and contractor management services for companies.