Depends on the sector. For example, in California's large-scale wildfire responses, forced prison labor in firefighting acts as an important auxiliary force. https://www.commonwealmagazine.org/los-angeles-firefighters-...
In Arkansas, agricultural work accounted for 17% of all prison labor assignments in 2021. https://www.prisonlegalnews.org/media/publications/Captive_L...
That doesn't answer at all.
17% of prison assignments might be 3 assignments for all I know.
I found a number in your document: "...1.2 million people incarcerated in state and federal prisons, over 65 percent work."
That's 780,000.
And there's 163 million working folks in the USA.
Prisoners power .4% of the economy.