Drexel Valves produces cast bronze valves on an assembly line. In the 3rd Quarter of the year, it produced 890 valves each 8-hour shift. If the production in the 4th Quarter of the year it produces 920 valves each 8-hour shift, productivity has changed by what percentage?
Round your answer as a percentage to two decmial places (e.g., 4.45). Do not include the percentage sign.