(AP) — Transportation Secretary Sean Duffy said air traffic controllers received 70% of their back pay Friday for working during the shutdown.

A number of controllers called out of work during the shutdown as they dealt with the financial pressure from going without pay for so long.

Some controllers even got side jobs to help make ends meet. That led to delays and other flight disruptions when the Federal Aviation Administration ran short of controllers at airport towers and other radar facilities.

Controller staffing improved significantly earlier this week as the shutdown drew to a close. Duffy said earlier this week that controllers would receive the rest of their back pay in the next few paychecks.

Duffy and President Donald Trump have also proposed that controllers who didn’t miss a shift during the shutdown should receive $10,000 bonuses. But the details of exactly who might get those checks haven’t been released.