Why is Zhuge Liang's age called Jian Xing Twelve Years?

Jianxing (May, 223 -237) was the first title of Liu Chan, the monarch of Shu and Han Dynasties in the Three Kingdoms period, with 15. This is also the second title of the Shu-Han regime. Zhuge Liang (181-23410-8 [1]), born in Yang Du, Xuzhou (now yinan county, Linyi, Shandong), was born in Kongming, an outstanding politician and prime minister of Shu and Han in the Three Kingdoms period. In the twelfth year (234), Yu Jianxing died in Wuzhangyuan (now Qishan, Baoji). When he was alive, he was named Hou of Wuxiang. After his death, he pursued loyalty to the marquis of Wuxiang. Because of its military ability, the Eastern Jin regime was posthumously named King Wu Xing. Representative prose works include An Example and A Book of Commandments. He once invented the wooden ox, the flying horse, the Kongming lantern and so on, and transformed the crossbow, called Zhuge Lian crossbow, which can hit all targets with one crossbow.