Passage: From its inception until the early 1990s, Vietnam Airlines was a minor carrier within the aviation industry as it was hampered by a variety of factors including the socio-economic and political situation of the country. With the government's normalization of relations with the United States, the airline was able to expand, improve its products and services, and modernize its ageing fleet. In 1996, the Vietnamese government brought together 20 service companies to form Vietnam Airlines Corporation, with the airline itself as the centrepiece. In 2010, the corporation was restructured into a limited liability company and renamed Vietnam Airlines Company Limited. A seven-seat management board, members of which are appointed by the Vietnamese Prime Minister, oversees the company.As passenger transport constitutes its core activity, Vietnam Airlines plays a crucial role in the economic development of the country. It owns 100% of Vietnam Air Service Company – a regional airline in southern Vietnam, 70% of the low-cost carrier Jetstar Pacific Airlines, and 49% of the Cambodian national airline Cambodia Angkor Air. In addition, the corporation earns revenue from airline catering and the maintenance and overhauling of aircraft through a number of its subsidiaries, including Vietnam Airlines Engineering Company and Vietnam Airlines Caterers. The company has also diversified its investments in the aircraft-leasing and airport ground-servicing industries, and is looking to manufacture aircraft components. It controls and operates a cargo division, Vietnam Airlines Cargo.

Question: How many companies did the Vietnamese government bring together?
20 service companies