The two pie charts compare different methods of communication used in 1962 and 1982.
We can see from the first pie chart in 1962, letter had the highest percentage in the three types of communication, taking up 50%. At that time, the percentage of telephone (35%) was much higher than that of computer (15%).
It can be seen from the second pie chart in 1982, the telephone, which was 60%, was the most popular form oi communication. 30% of people used computers to communicate with others. However, writing letter had the lowest percentage in the three forms of communication, which was only 10%.