An engineer planning to purchase a new $48,000 pickup truck wants to have 1/2 of the cost of the truck as a down payment before purchasing it. She wants to buy the truck five years from now and plans to begin saving by depositing $5000 into a savings account one year from now, and then increasing the deposit each year by a uniform amount. If the account earns interest at 6% per year, the amount she must increase her deposit each year is nearest to