The provided pie charts illustrate the sales of five different types of books over a 40-year period, beginning in 1972.
Overall, adult fiction and children’s fiction have exhibited a consistent upward trend, while the other categories have tended to decline over time. Notably, the most significant change occurred in the adult fiction category.
In 1972, sales of adult fiction and children’s fiction both started at the same proportion of 20%. However, adult fiction experienced substantial growth, increasing by 25% over the period and becoming the best-selling category by 2012. In contrast, children’s fiction gradually rose to 25% over the same 40 years. Meanwhile, the sales of travel books showed a slight increase of 3% in 1992 before sharply falling to 10% two decades later.
Examining the other categories, sales of biographies and miscellaneous books displayed a similar downward trend. Biographies experienced a slight decline to 15% in 1992, nearly halving to 8% by the end of the period. Despite being the leading category at the start, with around 25% of sales, the miscellaneous books saw a continuous decrease, dropping to 12% by 2012.