Qualifications and Criteria Standards for Foreigners Undertaking the Jobs Specified Under Subparagraph 1 to 6 of Paragraph 1 of Article 46 of the Employment Service Act Article 15

An employer who hires foreign pilots, as specified in the preceding Article, shall also train domestic pilots. The total number of foreign pilots hired by the employer may not exceed two point five (2.5) times of the sum of the total number of domestic pilots trained by the employer within seven (7) years prior to the application date, and the planned number of domestic pilots who are being or to be trained by the employer in the year of the application.
中文原文 外國人從事就業服務法第四十六條第一項第一款至第六款工作資格及審查標準第15條
聘僱前條外國籍駕駛員之雇主,應培訓本國籍駕駛員,其所聘僱外國籍駕駛員人數總和,不得超過自申請日起前七年內所自訓之本國籍駕駛員人數及該年度自訓本國籍駕駛員計畫人數總和之二點五倍。

English translation for reference only; the Chinese text prevails. Not legal advice.