A hospital bought a new medical laser machine for 2,812,500 $. The machine will generate a cash flow of 562,500 $ for six years, which is the expected useful life starting Year 1. The cost of capital is 8 percent. The expected salvage value for each year is shown below:

Year	Salvage Value
0	2,812,500
1	2,250,000
2	1,687,500
3	937,500
4	375,000
5	93,750
6	0

Using NPV, determine at what year the hospital should dispose of the equipment.

Please make certain that you show your calculations.