Belk procures curtains from its supplier for a cost of $$32$ per unit. The lead time to receive the order is $18$ days and Belk incurs a fixed order cost of $$863$ each time it places an order regardless of the number of units ordered. Demand for the curtains at the distribution center $($DC$)$ is constant at $239$ units per week. The holding cost per unit per year at the DC is $32\%$ of the per unit purchase cost. Belk currently orders $644$ units in each order. Assume Belk operates $7$ days per week, $52$ weeks per year, and $364$ days per year.

Calculate the number of orders per year for the current order quantity.