A certain model car in 1975 could be purchased for $ 3450. The value of the car initially declines, but eventually, cars in good condition become worth more than the original purchase price when they become antiques. For this particular car, the value, in dollars, t years after 1975 is given by V=18.75²-450t + 3450. How many years does it take for the value of the car to reach 5250? Round your final answer to three decimal places. Number of years =?