examined and worked for six months on probationary terms, before a long-term contract for 3–5 years was negotiated. Children were also no longer able to fill their parent's position automatically if their parents no longer worked for that company. Further changes included an expansion of reasons for which an employee could be fired, as well as the ability of an employer to refuse a routine job transfer. Workers were additionally to refrain from arguing with an unsatisfied customer to the point of losing a sale, which was particularly relevant in customer-based industries, such as restaurant businesses and retail. The Chinese Constitution was amended in 1992, when Deng Xiaoping garnered the political backing and CCP general secretary Jiang Zemin provided the initiative. The revised constitution scrapped the planned economy under public ownership in favor of a "socialist market economy" with "Chinese characteristics" that welcomed diversified forms of ownership, especially "privately-owned, individually-owned, and foreign-invested" enterprises. Still, public ownership at all levels of government remained dominant. At the 15th CCP National Congress in September 1997, Jiang announced that reforms of medium-sized and large state enterprises would be accelerated. He proposed two new initiatives: major lay-offs (laid-off workers in China still receive minimal salaries) and divestiture of smaller state enterprises through mergers, leasing, selloffs, and, in some cases, bankruptcy. Since then, the government has indicated it is willing to go much further, announcing plans to sell more than 10,000 of China's 13,000 medium-sized and large state enterprises. As a condition for joining the World Trade Organization in 2001, China had to "break the Iron Rice bowl", a step that was disputed by some economists. Efforts to break the iron rice bowl continued in Guangdong province in 2011 with a new plan of grassroots recruitment, employment by contract, and pay based on performance. The new arrangement will be included in the 12th five-year plan of the People's Republic of China (2011–2015). Current situation Since the start of post-Cultural Revolution reform in 1977, large numbers of workers in state-owned enterprises (SOEs) have been laid off while government workers retained job security. Up to this day, government officials () still have "iron rice bowl" lifelong job security, a circumstance often blamed for inefficiency and corruption. According to Statistical Bulletin on the Development of Human Resources and Social Security in 2015 published by Ministry of Human Resources and Social of the People's Republic of China on 30 May