The pie charts provide information on the proportions of five types of books offered by booksellers from 1972 to 2012. Overall, the sales of books related to adults and children followed similar upward trends, whereas the opposite was true for biographies, travel books, and other categories. Adult fiction books exhibited the highest sales with dominance during the period.
Focusing on increases first, adult fiction books started at 20% in 1972, after which they saw a modest increase to 25%. By 2012, they had more than doubled, reaching 45%. The percentage of sold children’s fiction books rose gradually from 1972 to 2012, reaching 25%.
By contrast, the sales of biographies, travel books, and other types of books decreased over the years. Figures for biographies and others were almost the same, the proportion of sales of books related to biography and other categories started at 20% and 25%, and this was followed by a slight fall to 15% and 20%, and almost halved to 8% and 10% by 2012. While the percentage of the sales of travel books rose insignificantly from 15% to 18% between 1972 and 1992, then started dropping to 10% in the following years.