355,000 between them is 177,500 each.
Retiring at 71, having worked since 20 is 51 years of work. Rounded up to the nearest guy, that's 3481 per year, rounded up to the nearest guy that's 10 per day.
However, if they only work a 5 day week, and typically only work 48 weeks per year, that gives only 240 working days per year. So that's an average of 14.5 men per work day. If each man is a 30 min slot, that's only 7.5 hrs work per day. Atypical job, but easily doable in typical hours...just wouldn't want to be number 15!