Siemens AG invests 80,000,000 to build a manufacturing plant to build wind turbines. The company predicts net cash flows of 16,000,000 per year for the next 8 years. Assume the company requires an 8% rate of return from its investments. (PV of $1, FV of $1, PVA of $1, and FVA of $1). (Use appropriate factor(s) from the tables provided.) (1) What is the payback period of this investment?