Trade Unions in India are registered and file annual returns under the Trade Union Act (1926). Statistics on Trade Unions are collected annually by the Labour Bureau of the Ministry of Labour, Government of India. As per the latest data, released for 2012, there were 16,154 trade unions which had a combined membership of 9.18 million (based on returns from 15 States – out of a total of 28 States and 9 Union Territories). The Trade Union movement in India is largely divided along political lines and follows a pre-Independence pattern of overlapping interactions between political parties and unions. The net result of this type of system is debated as it has both advantages and disadvantages. Bharatiya Mazdoor Sangh is the Largest Trade union of India.