(1) Ministry of Examination tried to make qualification standards consistent across various occupation categories because bar exams were held together with exams for other professionals and technologists.
(2) The process of trial and error to find the right passing rate.
After the 1980s, passing rates became higher due to two reasons:
(1) political liberalization and democratization in Taiwan, e.g. forming of the first opposition party DPP in 1986, terminating martial law and lifting bans on political parties and newspaper publications in 1987, presidential election by universal suffrage in 1996, citizens require higher passage rates to enter the bar.
(2) rapidly increasing undergraduate law departments, graduate law schools, and thus more students enter the job market and need to find jobs.
Therefore, in 1990, Ministry of Examination raised the passing rate to 16%, based on normal distribution/Tscore .