A computer manufacturing firm currently purchases microchips for $90each. The firm has the option to purchase its own manufacturing equipment for $100,000. This will enable it to produce its own microchips at a cost of $25 each. They will also have to pay Operation \& Maintenance costs of $7,000 per year. The firm will manufacture microchips for 10 years, after which the equipment has an expected salvage value of $20,000. The firm's MARR is 12%. At what annual production rate should the firm manufacture its own microchips