Onyx Company has prepared a static budget at the beginning of the month. At the end of the month, the following information has been retrieved from the records. Static budget: Sales volume: 1,000 units: Price: $70 per unit Variable expense: $32 per unit: Fixed expenses: $37,500 per month Operating income: $500 Actual results: Sales volume: 990 units: Price: $74 per unit Variable expense: $35 per unit: Fixed expenses: $33,000 per month Operating income: $5,610 Calculate the sales volume variance for fixed expenses