Canada's economic integration with the United States has increased significantly since World War II. The Automotive Products Trade Agreement of 1965 opened Canada's borders to trade in the automobile manufacturing industry. In the 1970s, concerns over energy self-sufficiency and foreign ownership in the manufacturing sectors prompted Prime Minister Pierre Trudeau's Liberal government to enact the National Energy Program (NEP) and the Foreign Investment Review Agency (FIRA). In the 1980s, Prime Minister Brian Mulroney's Progressive Conservatives abolished the NEP and changed the name of FIRA to Investment Canada, to encourage foreign investment. The Canada – United States Free Trade Agreement (FTA) of 1988 eliminated tariffs between the two countries, while the North American Free Trade Agreement (NAFTA) expanded the free-trade zone to include Mexico in 1994 (later replaced by the Canada–United States–Mexico Agreement). Canada has a strong cooperative banking sector, with the world's highest per-capita membership in credit unions.