That's really odd then.
311M over 9 days (as you don't pay wages on day 1) works out at around 34.55M* per day on wages, so I don't know how you have racked up such an amount.
278M in 9 days works out at around 30.88* per day, which is correct as my wage bill slightly increased the other day when I got my high 5 players into 6 star status.