Leas Corporation staffs a helpline to answer questions from customers. The costs of operating the helpline are variable with respect to the number of calls in a month. At a volume of 25,000 calls in a month, the costs of operating the helpline total $452,500.

To the nearest whole cent, what should be the average cost of operating the helpline per call at a volume of 25,300 calls in a month? (Assume that this call volume is within the relevant range.)

$18.93
$18.00
$17.89
$18.10