Jack Simpson, contract negotiator for Nebula Airframe Company, is currently involved in bidding on a follow-up government contract. In gathering cost data from the first three units, which Nebula produced under a research and development contract, he found that the first unit took 2,000 labor hours, the second took 1,700 labor hours, and the third took 1,600 hours. Use Exhibit 4A.6.

In a contract for three more units, how many labor hours should Simpson plan for? (Round your answer to the nearest whole number.)