we discovered that a number of people were unhappy because of the office was too cold. By turning up the thermostat we realized we could reduce employee turnover in the sales department to $5\%$ from $8\%.$ Please assume the sales department has $400$ people on average in the middle of each month.

We now know that each employee who leaves costs the company $$13,840.$ If we are able to reduce the sales department's turnover to $5\%$ per month, how much money will we save in a year?