The given charts detailed the proportion of 5-category books sold in bookseller from 1972 to 2012.
It is clear that Adult Fiction’ type book percentage rocketed immediately in each year and became the best-selling type book in 2012. But in contrast, the proportion of Biology decreased rapidly and almost became the least type book sold in same year.
In 1972, many individuals selected and bought Adult Fiction’s category book and simultaneously others people also bought Children Fiction’s type book. After many years, both of categories became the most selected-type in 2012 with the figure being 45% and 25% respectively.
In the others hand, Biology accounted for the same proportion of 2-category before but in many next years, it suddenly dropped down from a fifth to nearly one in ten and almost the least book-sold type in 2012. Beside that, Travel and others type book made up the largest proportion in 1972, but in contrast, they took up the small percentage of the charts being 10% and 12% respectively.