Your firm is considering purchasing a machine with the following annual, end-of-year, book investment accounts.

	Year 0		Year 1		Year 2		Year 3		Year 4
Gross investment	$	70,000	$	70,000	$	70,000	$	70,000	$	70,000
Less: Accumulated depreciation		0		17,500		35,000		52,500		70,000
Net investment	$	70,000	$	52,500	$	35,000	$	17,500	$	0

The machine generates, on average, $5,900 per year in additional net income. What is the average accounting return for this machine?