Question: Isabelle Guérin received the title of étoile from Rudolf Nureyev, director of the Paris Opera Ballet during what years?

Context articles: Attilio Labis
Palais Garnier
Flemming Flindt
François Alu
Kader Belarbi
Laurent Hilaire
Jean-Louis Aumer
Ghislaine Thesmar
Isabelle Guérin
Rudolf Nureyev

Attilio Labis (born 1936) is a French ballet dancer and teacher.
 He began his training at the Opéra de Paris when he was nine years old and rose through the ranks of the school.
 In 1952 he was accepted into the corps de ballet Paris Opera Ballet, but in 1958 he had to join the military.
 Upon the completion his military service, he came back and successfully auditioned for a "Premier Danseur" (First soloist) position after only one week of training.
 He was promoted to "Danseur Étoile" (principal dancer) approximately one year later, after André Malraux saw him dance "Pas de Dieux", a choreography by Gene Kelly, and recommended he be promoted.
 He performed as a "Danseur Étoile" (principal dancer) in the Paris Opera Ballet from 1960 to 1972, then taught the company as a ballet teacher until his retirement<br>
The Palais Garnier (] French    ) is a 1,979-seat opera house, which was built from 1861 to 1875 for the Paris Opera.
 It was called the Salle des Capucines, because of its location on the Boulevard des Capucines in the 9th arrondissement of Paris, but soon became known as the Palais Garnier, in recognition of its opulence and its architect, Charles Garnier.
 The theatre is also often referred to as the Opéra Garnier (French    ) and historically was known as the Opéra de Paris or simply the Opéra, as it was the primary home of the Paris Opera and its associated Paris Opera Ballet until 1989, when the Opéra Bastille opened at the Place de la Bastille.
 The Paris Opera now mainly uses the Palais Garnier for ballet.
Flemming Flindt (30 June 1936 – 3 March 2009) was a Danish choreographer born in Copenhagen.
 He studied at the Royal Danish Ballet and Paris Opera Ballet schools, joined the Royal Danish Ballet and was promoted to soloist in 1955.
 He guested with the London Festival Ballet in 1955, the Ballet Rambert in 1960, the Royal Ballet 1963 and the Bolshoi Ballet in 1968, becoming an "étoile" at the Paris Opera Ballet in 1961.
François Alu (born 1993 in Fussy, Cher, France) is a French "Premier Danseur" (first soloist), of the Paris Opera Ballet.
 He entered the Paris Opera Ballet School in 2004, and the Paris Opera Ballet in 2010.
 At his first promotion competition, he was promoted to Coryphée, dancing as a free variation the act II solo of Solor, from La Bayadère by Rudolf Nureyev.
 The next year, he was promoted to "Sujet" (soloist), dancing as a free variation the act III solo of Solor, from La Bayadère by Rudolf Nureyev.
Kader Belarbi (born 1962) is a French ballet dancer, choreographer and director.
 He spent his whole career in the Paris National Opera Ballet, between 1980 and 2008, and belongs to the company’s “Nureyev generation”, having been made an "étoile" (principal) by Rudolf Nureyev in 1989.
Laurent Hilaire (born 8 November 1962) is a French ballet dancer.
 Regarded as one of the greatest dancers to emerge from ballet over the past few decades, he was etoile (principal dancer) of the Paris Opera Ballet for 22 years.
 From 2011 he was the associate artistic director of the Paris Opera Ballet and a ballet master with the company from 2005 to 2014
Jean-Louis Aumer was a French danseur and choreographer, who was born in Strasbourg on 21 April 1774, and who died in Saint-Martin-de-Boscherville in July 1833.
 Educated at the school of the Paris Opera Ballet, he joined the company in 1801 after an initial engagement with Jean Dauberval in Bordeaux.
 The Paris Opera's "maître de ballet" Pierre Gardel presented an obstacle which led Aumer to choose the Théâtre de la Porte Saint-Martin as the venue for which to create his early ballets.
 Faced with the implacable competition from Gardel, Aumer left France for engagements in Kassel (1808–1814) and Vienna (1814–1820).
 Brief periods in Paris (1821–1822) and London (1824–1825) were followed by his return to the Paris Opera Ballet (1820–1831), where, enriched by the experience of working abroad, he engaged in a profound renovation of the French repertory, capped by his "chef-d'œuvre", "Manon Lescaut" (1830).
Ghislaine Thesmar (born 1943 in Beijing, China), a Ballerina, who studied at the Paris Conservatoire.
 In 1968, she married the dancer and choreographer Pierre Lacotte.
 Companies she danced with include Ballet du Marquis de Cuevas (1961), Lacotte's company, then the Paris Opera Ballet from 1972 to 1985; unusually, she joined the company directly as an "étoile" (principal).
 She led the Ballets de Monte Carlo with Lacotte from 1986 to 1988.
 She danced as a guest for the Rambert Ballet, the Grands Ballets Canadiens and the New York City Ballet.
 She has taught for the Paris Opera Ballet.
 She was frequently partnered by Michael Denard.
 Her most celebrated roles include Odette/Odile in "Swan Lake" and Giselle in "Giselle".
 The ballet film "La Sylphide" (1972) has been released twice on DVD/video and features Thesmar and Denard in the principal roles of the Sylph and the Scotsman, James.
Isabelle Guérin (born 1961) is a French ballet dancer.
 She was a member of the Paris Opera Ballet from 1978.
 In 1985, she received the title of étoile from Rudolf Nureyev.
 John Rockwell has described Guérin and Laurent Hilaire as "two of the Opera Ballet's greatest stars".
 She danced classical and modern repertoires until her retirement in 2001.
Rudolf Khametovich Nureyev (Bashkir: Рудольф Хәмит улы Нуриев , Tatar: Рудольф Хәмит улы Нуриев , Russian: Рудо́льф Хаме́тович Нуре́ев ; 17 March 1938 – 6 January 1993) was a Soviet ballet dancer and choreographer.
 He was director of the Paris Opera Ballet from 1983 to 1989 and its chief choreographer until October 1992.