West Bengal and cargo ship service to ports in India and abroad, operated by the Shipping Corporation of India. Ferries are a principal mode of transport in the southern part of the state, especially in the Sundarbans area. Kolkata is the only city in India to have trams as a mode of transport, and these are operated by the Calcutta Tramways Company. Several government-owned organisations operate bus services in the state, including the Calcutta State Transport Corporation, the North Bengal State Transport Corporation, the South Bengal State Transport Corporation, the West Bengal Surface Transport Corporation, and the Calcutta Tramways Company. There are
Economy of West Bengal 33% of the potato yield in 2004, despite accounting for only 7.55% of the population of India. The state's total financial debt stood at . Agriculture accounts for the largest share of the labour force. It contributed around 18.7% to the gross state domestic product (GSDP) in 2009–10. A plurality of the state's population are peasant farmers. Rice and potato are considered to be the principal food crops of West Bengal. West Bengal is the largest producer of rice in India with an annual output of around 16.1 million tonnes in FY 2015-16, and the second-largest producer of potatoes in