Passage: Economic liberalisation, begun in 1991, has caused India to become a fast growing major economy and a newly industrialised country.  Its gross domestic product ranks sixth in the world in market exchange rates and third in purchasing power parity.  Its per capita income ranks 133rd and 116th in the two measures.   India faces challenges of poverty, corruption, malnutrition, and inadequate public healthcare.  A nuclear weapons state and regional power, it has the second largest active military in the world and ranks high in military expenditure. India is a secular, federal republic, governed in a democratic parliamentary system, and administered in 29 states and seven union territories.  A pluralistic, multilingual and multi-ethnic society, India is home to 1.3 billion people.  It is also home to a high diversity of wildlife in a variety of protected habitats.

Question: When did economic liberalization start?
1991