When King Taksin, himself the son of a Chinese immigrant, ruled Thailand, King Taksin actively encouraged Chinese immigration and trade. Chinese settlers came to Siam in large numbers. Immigration continued over the following years, and the Chinese population in Thailand jumped from 230,000 in 1825 to 792,000 by 1910. By 1932, approximately 12.2 percent of the population of Thailand was Chinese. The early Chinese immigration consisted almost entirely of men who did not bring women. Therefore, it became common for male Chinese immigrants to marry local Thai women. The children of such relationships were called Sino-Thai or luk-jin (ลูกจีน) in Thai. These Chinese-Thai intermarriages declined somewhat in the early 20th century, when significant numbers of Chinese women also began immigrating to Thailand. Economic recession and unemployment forced many men to leave China for Thailand in search of work to seek wealth. If successful, they sent money back to their families in China. Many Chinese immigrants prospered under the "tax farming" system, whereby private individuals were sold the right to collect taxes at a price below the value of the tax revenues. The local Chinese community had long dominated domestic commerce and had served as agents for royal trade monopolies. With the rise of European economic influence, however, many Chinese shifted to opium trafficking and tax collecting, both of which were despised occupations. From 1882 to 1917, nearly 13,000 to 34,000 Chinese legally entered Thailand per year, mostly settling in Bangkok and along the coast of the Gulf of Siam. They predominated in occupations requiring arduous labor, skills, or entrepreneurship. They worked as blacksmiths, railroad labourers and rickshaw pullers. While most Thais were engaged in rice production, the Chinese brought new farming ideas and new methods to supply labor on its rubber plantations, both domestically and internationally. However, republican ideas brought by the Chinese were considered seditious by the Thai government. For example, a translation of Chinese revolutionary Sun Yat-sen's Three Principles of the People was banned under the Communism Act of 1933. The government had regulated Chinese schools even before compulsory education was established in the country, starting with the Private Schools Act of 1918. This act required all foreign teachers to pass a Thai language test and for principals of all schools to implement standards set by the Thai Ministry of Education. Legislation by King Rama VI (1910–1925) that required the adoption of Thai surnames was largely directed at