The Pie Chart Below Shows the Percentage of Five Kinds of Books Sold by a Bookseller Between 1972 and 2012

The pie chart below shows the percentage of five kinds of books sold by a bookseller between 1972 and 2012. Summarize the information by selecting and reporting the main features and making comparisons where relevant. The three diagrams demonstrate the proportion of preferred book types of people from three different years; 1972, 1992 and 2012. […]