Question: How long did the bombing of a Toronto–Montreal–London–Delhi route of Air India have an effect on Canada-India relations for?

full_context: Document 1: Indian Airlines Flight 427: Indian Airlines Flight IC427 was involved in an aircraft hijacking that took place in India between April 24 and April 25, 1993. Commandos from the National Security Guard (NSG) rescued all 141 hostages of the Indian Airlines Boeing 737, on the ground at Amritsar airport. The lone hijacker, Mohammed Yousuf Shah, was killed within 5 minutes of commandos entering the plane, before he could react and harm any of the hostages. The rescue was code-named Operation Ashwamedh.
Document 2: Tenerife airport disaster: On March 27, 1977, two Boeing 747 passenger jets, KLM Flight 4805 and Pan Am Flight 1736, collided on the runway at Los Rodeos Airport (now Tenerife North Airport), on the Spanish island of Tenerife, Canary Islands, killing 583 people in the deadliest accident in aviation history.
Document 3: Canada–South Korea Free Trade Agreement: The Canada–South Korea Free Trade Agreement (CKFTA) is a free trade agreement between Canada and South Korea. The agreement was concluded at the Blue House in Seoul on 11 March 2014 by Stephen Harper, the Prime Minister of Canada, and Park Geun-hye, the President of South Korea.
Document 4: Canada–South Korea relations: Canada–South Korea relations are foreign relations between Canada and the Republic of Korea. Canadian soldiers participated in the defense of South Korea during the Korean War. Full diplomatic relations between Canada and South Korea were established on January 14, 1963. Canada has an embassy in Seoul, and a consulate in Busan. South Korea has an embassy in Ottawa and three Consulates-General, in Montreal, Toronto and Vancouver. Both nations are full members of APEC, OECD and the G20.
Document 5: Canada–Panama Free Trade Agreement: The Canada–Panama Free Trade Agreement is a free trade agreement between Canada and Panama that went into effect April 1, 2013. The agreement was concluded on August 11, 2009 by Canadian Prime Minister Stephen Harper and Panamanian President Ricardo Martinelli and signed by the two countries' trade ministers on May 14, 2010. The agreement was approved by both countries' parliaments by December 2012, allowing the agreement to come into effect. The agreement eliminates Panamanian tariffs on 90% of goods from Canada. The remaining 10% will be phased out within the next 10 years. Canada will remove 99% of its tariffs on goods from Panama. Canada will keep tariffs on some imports of sugar, poultry, eggs and dairy products. Panama will end its ban on beef from Canada which was initiated after cases of mad cow disease were found in Canada in 2003.
Document 6: Air Canada Flight 621: The Air Canada Flight 621 crash near Toronto Pearson International Airport, took place on July 5, 1970, when an Air Canada Douglas DC-8, registered as CF-TIW, was attempting to land. It was flying on a Montreal–Toronto–Los Angeles route.
Document 7: ICICI Bank Canada: ICICI Bank Canada is a wholly owned subsidiary of ICICI Bank Limited, India’s largest private sector bank. ICICI Bank Canada’s corporate office is located in Toronto, Ontario. Established in December 2003, ICICI Bank Canada is a full-service direct bank with an asset base of about $6.5 billion as at December 31, 2016. It is governed by Canada’s Bank Act and operates under the supervision of the Office of the Superintendent of Financial Institutions. The bank has eight branches in Canada: one in Calgary, Alberta; one in Surrey, British Columbia; and six in the Greater Toronto Area, Ontario.
Document 8: Indian Airlines flight 814 hijacking: Indian Airlines Flight 814 commonly known as IC 814 was an Indian Airlines Airbus A300 en route from Tribhuvan International Airport in Kathmandu, Nepal to Indira Gandhi International Airport in Delhi, India on Friday, 24 December 1999, when it was hijacked. Harkat-ul-Mujahideen was accused of the hijacking.
Document 9: 1985 in aviation: This is a list of aviation-related events from 1985. It remains one of the deadliest years in aviation history for aviation disasters, including the crash of Japan Airlines Flight 123, bombing of Air India Flight 182, crash of Arrow Air Flight 1285, crash of Aeroflot Flight 7425, crash of Iberia Airlines Flight 610, Delta Air Lines Flight 191, Galaxy Airlines Flight 203, and British Airtours Flight 28M, a mid-air collision between Aeroflot Flight 8381 and a Soviet Air Forces transport aircraft, the hijacking of Egyptair Flight 648, and various crashes and other incidents with under 50 fatalities. August 1985 remains the worst single month for commercial aviation fatalities in history.
Document 10: Air India Flight 182: Air India Flight 182 was an Air India flight operating on the Toronto–Montreal–London–Delhi route. On 23 June 1985, the Boeing 747-237B serving the flight (c/n 21473/330, registration VT-EFO , "Emperor Kanishka") was destroyed by a bomb at an altitude of 31000 ft . It crashed into the Atlantic Ocean while in Irish airspace. It was the first bombing of a 747 jumbo jet. A total of 329 people were killed, including 268 Canadian citizens, 27 British citizens and 24 Indian citizens. The incident was the largest mass murder in Canadian history, and the deadliest incident in the history of Air India. It was the deadliest terrorist attack involving an airplane until the September 11, 2001, attacks. The bombing of Air India 182 occurred at the same time as the Narita Airport bombing. Investigators believe that the two plots were linked, and that those responsible were aiming for a double bombing. However, the bomb at Narita exploded before it could be loaded onto the plane.
Document 11: Pan Am Flight 73: Pan Am Flight 73, a Pan American World Airways Boeing 747-121, was hijacked on September 5, 1986, while on the ground at Karachi, Pakistan, by four armed Palestinian men of the Abu Nidal Organization. The aircraft, with 360 passengers on board, had just arrived from Sahar International Airport in Mumbai, India, and was preparing to depart Jinnah International Airport in Karachi for Frankfurt Airport in Frankfurt am Main, West Germany, ultimately continuing on to John F. Kennedy International Airport in New York City, United States. A June 2001 grand jury charged that the militants were planning to use the hijacked plane to pick up Palestinian prisoners in both Cyprus and Israel.
Document 12: Canada–United States relations: Relations between Canada and the United States of America historically have been extensive, given a shared border and ever-increasing close cultural, economical ties and similarities. The shared historical and cultural heritage has resulted in one of the most stable and mutually beneficial international relationships in the world. For both countries, the level of trade with the other is at the top of the annual combined import-export total. Tourism and migration between the two nations have increased rapport, but border security was heightened after the terrorist attacks in the United States on September 11, 2001. The U.S. is ten times larger in population and has the dominant cultural and economic influence in the world. Starting with the American Revolution, when anti-American Loyalists fled to Canada, a vocal element in Canada has warned against US dominance or annexation. The War of 1812 saw invasions across the border. In 1815, the war ended with the border unchanged and demilitarized, as were the Great Lakes. The British ceased aiding First Nation attacks on American territory, and the United States never again attempted to invade Canada. Apart from minor raids, it has remained peaceful.
Document 13: Canada–India relations: Canada–India relations, or Indo-Canadian relations, are the longstanding bilateral relations between Canada and the Republic of India, which are built upon a "mutual commitment to democracy", "pluralism", and "people-to-people links", according to the government of Canada. In 2009, bilateral trade between India and Canada was at about C$4.14 billion. Most notably, the bombing of Air India Flight 182 by Canadian residents, killing a vast quantity of Canadian citizens, had effects on relations for about 20 years. India's Smiling Buddha nuclear test added strains to the relationship between the two nations, with allegations that India broke the terms of the Colombo Plan. Although Jean Chrétien and Roméo LeBlanc both visited India in the late 1990s, relations were again halted, albeit temporarily, after the Pokhran-II tests. India and Canada are taking steps to become strategic partners, with Prime Minister Stephen Harper making a state visit in 2012. Both are former British colonies and full members of the Commonwealth of Nations, with Canada being home to one of the largest Indian diasporas in the world.
Document 14: Canada India Foundation: The Canada India Foundation is a Canadian non-profit organisation established in 2007. The main stated objective of CIF comprises promoting Canada-India relations through their active intervention in public policy which would cover domestic policies and bi-lateral issues affecting the Indo-Canadian community, including issues such as culture, education, trade and investment, immigration, diplomatic, political, and strategic relations.
Document 15: Pan Am Flight 103: Pan Am Flight 103 was a regularly scheduled Pan Am transatlantic flight from Frankfurt to Detroit via London and New York. On 21 December 1988, N739PA, the aircraft operating the transatlantic leg of the route, was destroyed by a bomb, killing all 243 passengers and 16 crew, in what became known as the Lockerbie bombing. Large sections of the aircraft crashed onto residential areas of Lockerbie, Scotland, killing 11 more people on the ground.
ground_truth: about 20 years