How do you prove unemployment history?

I’m applying for a training course at my local community college. It’s grant funded and will be tuition free to those who are eligible. To meet the requirements I must 1) have been unemployed for at least 20 weeks in the past 5 years, and 2) be currently unemployed.

How would I show proof of this? What kind of documentation would I need to show?

I plan on contacting the department of labor when they’re open, but thought someone here might have some helpful info.