Seal script is one of a series of handed down characters created by our ancestors. The unification of the six countries in the Qin Dynasty was a watershed. After Qin Shihuang unified the six countries, he executed the same script. Among them, the script is Xiao Zhuan, also called Qin Zhuan, as the unified language of the country.
The characters used in this period are all Xiao Zhuan, so it is hard to say how many characters are like Oracle Bone Inscriptions, which is the earliest one found so far. Especially now, as a calligraphy font, many characters can be written as Xiao Zhuan.