An egg develops in an ovarian follicle before ovulation. At the beginning of its development, the follicle has a diameter of 35×10−3 mm35 \times 10^{-3}\text{ mm}35×10−3 mm. Just before ovulation, this follicle has grown to a diameter of 18 mm18\text{ mm}18 mm.
Calculate the increase in the diameter of the follicle.
Give your answer to 2 decimal places.