There are 135 people in a sport centre. 73 people use the gym.
59 people use the swimming pool.
31 people use the track.
19 people use the gym and the pool.
9 people use the pool and the track.
16 people use the gym and the track.
4 people use all three facilities.
A person is selected at random.
What is the probability that the person uses exactly one of the facilities?