Question: When did the maker of the Acura Legend, the manufacturer of Toyopet Master, and Nissan open US assembly plants?

Context paragraphs:
paragraph_text: BMW released the first iPod automobile interface, allowing drivers of newer BMW vehicles to control an iPod using either the built-in steering wheel controls or the radio head-unit buttons. Apple announced in 2005 that similar systems would be available for other vehicle brands, including Mercedes-Benz, Volvo, Nissan, Toyota, Alfa Romeo, Ferrari, Acura, Audi, Honda, Renault, Infiniti and Volkswagen. Scion offers standard iPod connectivity on all their cars.
title: IPod
paragraph_text: Second generation Acura RDX 2013 Acura RDX Overview Production Mar 2012 -- present Model years 2013 -- present Assembly East Liberty, Ohio, United States East Liberty Auto Plant Powertrain Engine 3.0 L J30Y1 V6 (China Only) 3.5 L J35Y V6 Transmission 6 - speed automatic Dimensions Wheelbase 105.7 inches (9 foot 6 inches Length 183.7 inches (16 ft 7 inches Width 73 inches (6 foot 7 inches) Height 64.2 inches (5 foot 8 inches Curb weight 3,717 lb (1,686 kg) (FWD) 3,838 lb (1,741 kg) (AWD)
title: Acura RDX
paragraph_text: Datsun (, ) is an automobile brand owned by Nissan. Datsun's original production run began in 1931. From 1958 to 1986, only vehicles exported by Nissan were identified as Datsun. By 1986 Nissan had phased out the Datsun name, but re-launched it in June 2013 as the brand for low-cost vehicles manufactured for emerging markets.
title: Datsun
paragraph_text: The Nissan Rogue is a compact crossover SUV produced by the Japanese automaker Nissan. It made its debut in October 2007 for the 2008 model year. The current model, the second generation launched in 2013, is the North American version of the Nissan X-Trail. It is currently Nissan's best - selling vehicle in the United States.
title: Nissan Rogue
paragraph_text: Some buyers lamented the small size of the first Japanese compacts, and both Toyota and Nissan (then known as Datsun) introduced larger cars such as the Toyota Corona Mark II, the Toyota Cressida, the Mazda 616 and Datsun 810, which added passenger space and amenities such as air conditioning, power steering, AM-FM radios, and even power windows and central locking without increasing the price of the vehicle. A decade after the 1973 oil crisis, Honda, Toyota and Nissan, affected by the 1981 voluntary export restraints, opened US assembly plants and established their luxury divisions (Acura, Lexus and Infiniti, respectively) to distinguish themselves from their mass-market brands.
title: 1973 oil crisis
paragraph_text: The first-generation Acura RL was a rebadged version of the third-generation Honda Legend, and was first introduced to the North American market in 1996, to replace the second-generation Acura Legend. The second-generation Acura RL was a rebadged version of the fourth-generation Honda Legend, introduced to the North American market in September 2004, as a 2005 model. This iteration of the RL received an extensive mid-generational facelift for the 2009 model year, and a further update for 2011. The third-generation debuted for the 2014 model year as the Acura RLX.
title: Acura RL
paragraph_text: Seattle remained the corporate headquarters of Boeing until 2001, when the company separated its headquarters from its major production facilities; the headquarters were moved to Chicago. The Seattle area is still home to Boeing's Renton narrow-body plant (where the 707, 720, 727, and 757 were assembled, and the 737 is assembled today) and Everett wide-body plant (assembly plant for the 747, 767, 777, and 787). The company's credit union for employees, BECU, remains based in the Seattle area, though it is now open to all residents of Washington.
title: Seattle
paragraph_text: From September 1947, Toyota's small - sized vehicles were sold under the name ``Toyopet ''(トヨペット). The first vehicle sold under this name was the Toyopet SA, but it also included vehicles such as the Toyopet SB light truck, Toyopet Stout light truck, Toyopet Crown, Toyopet Master, and the Toyopet Corona. The word`` Toyopet (Japanese article)'' was a nickname given to the Toyota SA due to its small size, as the result of a naming contest the Toyota Company organized in 1947. However, when Toyota eventually entered the American market in 1957 with the Crown, the name was not well received due to connotations of toys and pets. The name was soon dropped for the American market, but continued in other markets until the mid-1960s.
title: Toyota
paragraph_text: The Acura RLX is a full-size luxury sedan manufactured by Honda and sold under their Acura division, released in 2013. Succeeding the Acura RL, the RLX offers two versions, a front-wheel drive base model equipped with Acura's Precision All-Wheel Steer (P-AWS) four-wheel steering system, and a hybrid variant featuring SH-AWD that serves as Acura's flagship. The JDM version, the Honda Legend, is only offered with the SH-AWD powertrain.
title: Acura RLX
paragraph_text: The Jonga was a Nissan designed vehicle used by the Indian Army. Jonga was an acronym for Jabalpur Ordnance aNd Guncarriage Assembly.
title: Jonga
paragraph_text: The Infiniti J30, or Nissan Leopard J Ferie in Japan, was a rear wheel drive luxury car. The J30 went into production on April 7, 1992 as a 1993 model to replace the M30 (which was a coupe), and was launched in the United States after its competitor, the Lexus GS. The car was designed to slot between the smaller G20 and the larger Q45, as Infiniti's first mid-size sedan to compete directly with the Acura Legend. Also, it was fairly small but featured rounded styling uncharacteristic of the crowded executive car class, that is now reminiscent of a four-door coupé. Chief designer for the J30 was Jerry Hirshberg, president of Nissan Design International (NDI) and exterior designer Doug Wilson in 1988-1989. Design work was frozen in 1989. In a promotional video produced in 1994, it was referred to as a "personal luxury sedan" as attempt to define it as a four-door coupé. It has the round looks of the Nissan Altima/Bluebird U13.
title: Infiniti J30
paragraph_text: The Acura Legend is a mid-size luxury/executive car manufactured by Honda. It was sold in the U.S., Canada, and parts of China under Honda's luxury brand, Acura, from 1985 to 1995, as both a sedan, which was classified as a full-size car, and a coupe, which was classified as a mid-size car (similar to how the Honda Accord is set up today). It was the first flagship sedan sold under the Acura nameplate, until being renamed in 1996 as the Acura 3.5RL. The 3.5RL was the North American version of the KA9 series Honda Legend.
title: Acura Legend
paragraph_text: Janesville Assembly Plant is a former automobile factory owned by General Motors located in Janesville, Wisconsin. Opened in 1919, it was the oldest operating GM plant when it was largely idled in December 2008, and ceased all remaining production on April 23, 2009. The demolition of the plant began in April 2018.
title: Janesville Assembly Plant
paragraph_text: Ford South Africa was based in Port Elizabeth (now part of the Eastern Cape province) and had been operating since 1923. In the early 1980s, it had both a vehicle assembly plant and an engine plant in Struandale, together with an older assembly plant in Neave. After the merger with Sigma and the formation of Samcor, the engine plant continued to be operated by Samcor and in 2015 is still operating under Ford ownership. Both the assembly plants were closed and all vehicle production transferred to Samcor's Silverton Assembly Plant in Pretoria. The Struandale assembly plant was subsequently sold to Delta Motor Corporation (General Motors).
title: Samcor
paragraph_text: The Toyopet Master range also included the Masterline RR16 pickup, the Masterline RR17 van and the Masterline RR19 double pickup (with two rows of seats). They were introduced in November 1955, originally only as a single-cab pickup and a van. The double pickup was added in August 1956, around which time the engine was upgraded to provide . These replaced the SG commercial models and were the first car-based trucks to enter production in Japan. The Masterline commercial models were carried over after the discontinuation of the Master. They were built until replaced by a new Crown-based Masterline in March 1959, for the Toyota Store sales channel. A smaller Coronaline version was also developed to be sold through Toyopet dealers.
title: Toyopet Master
paragraph_text: The Packard plant was opened in 1903 and at the time was considered the most modern automobile manufacturing facility in the world, with skilled craftsmen involved in over eighty trades. The factory complex closed in 1958, though other businesses operated on the premises or used it for storage until the late 1990s.
title: Packard Automotive Plant
paragraph_text: Norfolk Assembly was a Ford manufacturing plant that opened on April 20, 1925 on the Elizabeth River, near downtown Norfolk, Virginia -- closing in 2007.
title: Norfolk Assembly
paragraph_text: The Mercedes-Benz T2 was a transporter manufactured by Daimler-Benz. The T2 is also known as the "Düsseldorf transporter", since it was built in Düsseldorf from 1967 on. The third series, built from 1996 at Ludwigsfelde, was branded the Mercedes-Benz Vario. Some T2s were assembled by Mercedes-Benz España in their Alcobendas assembly plant.
title: Mercedes-Benz T2
paragraph_text: By the early 1960s, the US had begun placing stiff import tariffs on certain vehicles. The so - called ``chicken tax ''of 1964 placed a 25% tax on imported light trucks. In response to the tariff, Toyota, Nissan Motor Co. and Honda Motor Co. began building plants in the US by the early 1980s.
title: Toyota
paragraph_text: The Acura RL is a mid-sized / executive luxury car that was manufactured by the Acura division of Honda for the 1996–2012 model years over two generations. The RL was the flagship of the marque, having succeeded the Acura Legend, and was replaced in 2013 by the Acura RLX. All models of the Legend, RL and RLX lines have been adapted from the Japanese domestic market Honda Legend. The model name "RL" is an abbreviation for "Refined Luxury."
title: Acura RL

Reasoning steps:
Who made Acura Legend? >>>> Honda
Toyopet Master >> manufacturer >>>> Toyota
When did Honda , Toyota and Nissan open US assembly plants? >>>> 1981

Answer: spans: 1981