A decade's worth of tax returns provides an interesting insight into how people prefer to work

More and more Americans are moving away from traditional jobs, and choosing to be self-employed or do freelance work instead.

According to the Bureau of Labor Statistics, self-employed workers now make up 10% of the workforce overall.

That's nearly 15 million workers in the US.

Those numbers have grown considerably over the past decade, as shown in the two charts below from Zen99, a startup offering tax help to freelancers.

The number of people claiming self-employment income on their tax returns rose steadily between 2002 and 2012, the latest data available.

During those ten years, there was an average annual growth rate of 2.5%, compared to just a 1.1% yearly increase in the number of people filing tax returns overall.

Not only that, but self-employed workers are reporting more income than ever.

The total amount of taxes that they pay has nearly doubled, rising from $37 billion to $63 billion. That adds up to 72% growth over the measured time frame.

It's likely that some of these workers are reporting income from a part-time side hustle. As Zen99 notes, nearly 13% of all tax returns now include income from freelance work.

Since only 10% of the workforce is considered self-employed by the BLS, the other 3% might plan to keep their day jobs - or they're just waiting to take the plunge.