You have hired labors with the following condition: they work 55 hours per week for 25 weeks, 40 hours per week for 23 weeks, and they get "paid vacation/holiday" for 4 weeks a year. You have agreed on wage rate of $31 per hour, and 40% extra for any hour that they work over 40 per week. If the total annual benefit for a labor is calculated as a fix amount of $20,000, calculate the "burdened hourly wage rate" based on "billable hours