I think that must be somebody’s estimate or maybe just guess as to the total number of employees in the industry.

I seems a bit high to me, but I don’t know anything about the industry. FWIW, around 170k people die per day.

https://news.ycombinator.com/item?id=43918053

This doesn’t establish any sort of mathematical bounds, but it gives an idea of the size of the problem. I suspect 100k employees is an over-estimate just because a lot of people are uninsured…