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): $ Sales Variable expenses Contribution margin Fixed expenses Net operating income 23,000 13,000 10,000 8,500 1,500 $ Required: Using the degree of operating leverage, what is the estimated percent increase in net operating income of a 4% Increase in sales? (Do not round intermediate calculations, Round your answer to 2 decimal places.) Percent increase in net operating income %