A small company's accountant never learned the meaning of FOB Shipping Point and FOB Destination. Consequently, the company determined its ending inventory balance in 2017 was $32,000 when it should have been $38,000. The company made a similar mistake in 2018, and ending inventory was understated by $4500. What is the cumulative effect of these errors on Net Income for 2017 and 2018? (State the amount and whether NI was understated or overstated).