A company has improved its production process. Under the old process, 15 workers could produce 87 units per hour, and materials cost $49 per unit of output. Workers are paid $22 per hour and the finished product is sold for $296 per unit. After the improvement, materials costs have been reduced by $5 per unit of output, but it now takes three more workers to make the same amount of output. What is the percentage change in multifactor productivity?