21 Oslo Company prepared the following contribution format income statement based on a sales volume of 1,000 units (the relevant range of production is 500 units to 1,500 units): Part 12 of 12 Sales 03 02:26:26 $ 20,000 Variable expenses Contribution margin Fixed expenses 12,000 5,000 6,000 Net operating income $2,000 Check my Print 13. Using the degree of operating leverage, what is the estimated percent increase in net operating income of a 5% increase in sales? Increase in net operating income