Wind energy is one of the most fastest-growing segments of the energy production industry in the United States. A manufacturer makes several sizes of wind turbines. Wind turbine blades are mounted on a tower that is made of three sections of the tower is modeled by a cylinder with diameter of 15 feet. The table gives information about wind turbines.

Energy produced by each wind turbine depends on the local wind speed. The monthly energy production for one of the wind turbines is shown in the graph.

QUESTION:
Type your answer in the box. You may use numbers and/or a negative sign (-) in your answer. What is the difference in kliowatt hours of monthly energy production between an average local wind speed of 15 miles per hour and an average local wind speed of 10 miles per hour?