Pie charts illustrate the sales of different books by one bookseller over a 40-year period, from 1972 to 2012.
Overall, the sales of both children and adults fiction books increased, while the opposite is true for biography. Although travel books saw a rise in the middle of the period, sales then went down. Notably, the category named ”others” were the most sold in first year; however, adult’s fiction books surpassed it in the final year.
Considering genres that experienced an increase in sales, both children and adults fiction books started at a roughly fifth in 1972. While the former rose gradually to 25% over the period, the latter showed significant rise to 45% in 2012, becoming the most sold book among all four genres. As for the sale of travel books, it saw a small decrease from 15% to 10%, despite a rise to 18% in 1992.
In stark contrast, biography books sale went down by 5% from 20% to 15% over two decades, eventually accounting for 8% at the end of the period and becoming the least sold ones. The sale of the category named ”others” made up 20% and dropped gradually to 8% in the last year.