More than 500 employees will end their academic careers with Gwinnett County’s public school system at the end of this school year.

The workers are retiring; many of them have spent their adult lives working in Georgia’s largest school system. Most of the retirees are teachers. Others have worked as bus drivers, cafeteria workers, counselors, principals and in building maintenance. Gwinnett has about 22,000 employees.

Here’s a by-the-numbers breakdown of the retirees:

539 — the number of retirees

10 — the number of principals retiring

13,216 — how many years they’ve spent working in education

52 — the percentage of them who’ve worked their entire careers in education

21 — how many of them have worked more than 40 years in education