Preble Company manufactures one product. Its variable manufacturing overhead is applied to production based on direct labor$-$hours and its standard cost card per unit is as follows:

Direct materials: $5$ pounds at $$7$ per pound $ $35$

Direct labor: $3$ hours at $$16$ per hour $48$

Variable overhead: $3$ hours at $$4$ per hour $12$

Total standard cost per unit $ $95$

The planning budget for March was based on producing and selling $30,000$ units. However, during March the company actually produced and sold $34,000$ units and incurred the following costs:

Purchased $175,000$ pounds of raw materials at a cost of $$6\mathrm{.}80$ per pound. All of this material was used in production.

Direct laborers worked $71,000$ hours at a rate of $$17$ per hour.

Total variable manufacturing overhead for the month was $$340,090.$

$15.$ What is the variable overhead efficiency variance for March?