A quick search of their cited source shows this to be incorrect (or misleading, at least). Here's a few corresponding values (Total Cost of Employment = salary + overtime + vacation/sick time value + employer contributions to medical + employer contribution to pension + employer 401k matching + 'misc')(Cash = salary + overtime):
- Customer Service Clerk: 61k cash, 85k TCOE
- A-Line Train operator: Hard to say, because the range goes from 7k cash to 122k (although half of that high number was overtime). It looks like the lowest paid operator that's probably full time is around 40k cash, 74k TCOE
- Elevator worker: I couldn't find this job, but a "maintenance engineer" is 68k Cash, 106 TCOE.