How many years since Fu Xi ?

According to two ancient books:

from the book of The Lie Zi ( chapter 7: Yang Chu《列子·楊朱》) :

" Certainly, it is difficult to record how many years from the ancient times to now, however, since Fu Xi, now it have been more than 300,000 years".

and, from " Yi Wei Bian Zhong Bei " 《易緯辨終備》, written by Zheng Xuan 鄭玄 (127-200) in Han dynasty, (Emperor Shun of Han 漢順帝, Yonghe 136 永和元年) :

" it have been 493,989 years since Fu Xi."