The Emporium is a store that sells everything from bells and whistles to kittens and puppies. Their store offers delivery services to all customers that live within 2.5 miles of the store. Because of this, their delivery staff is always making trips to drop off goods to the local townsfolk. Orders are placed in such a way that the distance that delivery drivers must go is uniformly distributed between 0 and 5 miles (round trip). What is the probability that a delivery driver goes less than 2.5 miles on his delivery (round trip)?