Farmer Jones wants to convert his farm into a golf course. He asked you to determine his rate of return on the basis of the following estimates: development cost for each of the first 3 years, $80 000; construction of a clubhouse in Year 4, $240 000; upon his retirement in 15 years, improvements in the property will yield him $200 000; net returns from the operation of the golf course will be nil for the first 3 years and $100 000 per year thereafter until his retirement.