due to the relative power of KMT refugees from Wu-speaking Zhejiang, Chiang Kai-shek's home province. The Mandarin Promotion Council (now called National Languages Committee) was established in 1946 by Chief Executive Chen Yi to standardize and popularize the usage of Mandarin in Taiwan. The Kuomintang heavily discouraged the use of Southern Min and other non-Mandarin languages, portraying them as inferior, and school children were punished for speaking their non-Mandarin native languages. Guoyu was thus established as a lingua franca among the various groups in Taiwan at the expense of existing languages. Post-martial law Following the end of martial law in 1987, language policy in the country underwent liberalization, but Guoyu remained the dominant language. Local languages were no longer proscribed in public discourse, mass media, and schools. English and "mother tongue education" (; mǔyǔ jiàoyù) — Minnanyu and Hakka — were introduced as elective subjects in primary school in 2001. Greater time and resources are devoted to both Mandarin and English, which are compulsory subjects, compared to mother tongue instruction. Mandarin is spoken fluently by the vast majority of the Taiwanese population, with the exception of some of the elderly population, who were educated under Japanese rule. In the capital of Taipei, where there is a high concentration of Mainlander descendants who do not natively speak Minnanyu, Mandarin is used in greater frequency and fluency than other parts of Taiwan. The 2010 Taiwanese census found that in addition to Mandarin, Minnanyu was natively spoken by around 70% of the population, and Hakka by 15%. A 2004 study found that Mandarin was spoken more fluently by Hakka and Taiwanese aboriginals than their respective mother tongues; Hoklo groups, on average, spoke better Minnanyu, but Hoklo under 50 years old still spoke significantly better Mandarin (with comparable levels of fluency to their usage of Minnanyu) than the elderly. Overall, while both national and local levels of government have taken some measures to promote the use of non-Mandarin Chinese languages, younger generations generally prefer using Mandarin. Government statistics from 2020 found that 66% of Taiwanese residents use Guoyu as their primary language, and another 31% use it as a secondary language (32% used Minnanyu as their primary language, and 54% used it as a secondary language). Guoyu is the primary language for over 80% of people in the northern areas of Taipei, Taoyuan, and Hsinchu. Youth is correlated with use of Guoyu: in 2020,