The given diagram depects the daily british audience of radio and television in the year 1992.
Overall, the television has not much audience at noon. It starts very low, but faces a sharp rise at evening and midnight. Then, it starts to go low by early morning. The opposite happens for the people who listen to radio, the numbers start high, and gradually give their place to the TV audience. Regarding television at 6 am no one watches TV. Then, the numbers rise up by almost 2 pm. It is almost more than a tenth at that hour, and a rocket change accures at 4 pm untill midnight. The numbers in this time-line go as high a approximately half of the UK. After that hour forward, the numbers decline to a low as about 0.
Turning to radio listeners less than a third of the UK have their radio on by 10 am, the numbers fall to almost one out of ten at 2 pm. At that time of the day television takes the place of radio. The numbers try to rise at 4 pm by about 5%, but the decline continues by midnight. The number is now under 10%, after midnight almost no one has their radio on, maybe only a few.