Pearl Manufacturing is considering an investment in equipment costing $660,000. The equipment will be depreciated on the straight-line basis over an eight-year period with an estimated residual value of $120,000. The investment is expected to generate annual net cash inflows of $135,000 for 8 years. Using the accounting rate of return model, what is the minimum average annual operating income that must be generated from this investment in order to achieve a 14% accounting rate of return?