Question: What year did the opera singer who is the subject of Becoming Traviata leave the opera stage?

Context articles: Luo Pinchao
Gioconda Vessichelli
James Westman
Rose Bampton
Natalie Dessay
Virginia Zeani
Karel Kalaš
La Traviata (1983 film)
Caterina Jarboro
Becoming Traviata

Luo Pinchao (June 1912 – July 15, 2010) was a Cantonese opera stage actor who started to perform in 1930.
 He was eventually recognized as the world's oldest opera singer by the Guinness World Records.
Gioconda Vessichelli (born in Rome, Italy) is an opera singer.
 Gioconda is the inventor and pioneer of BollywoOPERA style.
 She has sung in the Bollywood movie "Prague "in 2013, and she has given her voice for the Bollywood movie "Mary Kom" on the song "Ziddi dil" together with Vishal Dadlani.On 19th May 2017 her song "Itni si baat hai" has been released by the label T-series.
 On 20 December 2014 the song "Thodi Daaru" was released featuring Mika Singh.
 Gioconda has done live performances as first fusion ever between opera and classical Hindi music with artists of the caliber of Grammy Award winner Sukhwinder Singh, Hari Haran, Gino Banks, Niladri Kumar, Silvaganesha, in festivals and auditoriums like Nehru Centre[20] in Mumbai.
 She collaborates with Anup Jalota, and many others.
 On 31 March 2016 her international video "We are one" in which she sings and acts together with Anup Jalota for peace in the world has been launched from the Minister of India in Delhi.
 She is in the annual book of Italian opera singer for having sung in the first world edition of contemporary opera at "Teatro comunale di Modena", broadcast on Italian state radio RAI.
 Gioconda is the first singer in the premiere world ever of the contemporary opera “Lavinia fuggita” by Matteo d’Amico.
 She has two degrees in opera singing and musicology from Italian conservatory "Santa Cecilia" and international high school of opera "H.Wolf".
 The tenor Luciano Pavarotti has been her teacher, among other opera singers who selected her as one of the best students.
 She was selected as best singer at accademia rossiniana in Pesaro and she debuts the role of "Madama cortese" in "il viaggio a Reims" by Rossini with the symphonic orchestra of Rof at Rossini theatre in Pesaro.
 She sings again in a Rossini opera at Ercolano international opera season in "Il barbiere di Siviglia" and at teatro Politeama opera season in Lecce.
 After Rossini she debuts "Carmen" by Bizet.
 Her interpretation of the role "Mimì" in the opera "La Boheme" by Puccini received positive critiques.
James Westman (born September 16, 1972) is a Canadian baritone known for his interpretation of the Verdi, Puccini and bel canto operatic repertoire, and particularly his signature role of Germont in "La traviata", which he has sung in over 150 performances, with opera companies such as San Francisco Opera, Houston Grand Opera, Pittsburgh Opera, Florida Grand Opera, Graz Opera, Santa Fe Opera, Chicago Lyric Opera, Opéra de Montréal, Los Angeles Opera, Grand Théâtre de Bordeaux, Canadian Opera Company, Boston Lyric Opera, Cologne Opera, Vancouver Opera, English National Opera, San Diego Opera, Dallas Opera, Utah Opera, and Opera Theatre of St. Louis.
 On January 29, 2011 Westman created the lead role of Sandy Keith In the world premiere of Bramwell Tovey's The Inventor.
 In 2017 he played Sir John A. MacDonald in Harry Somers's Louis Riel for the Canadian Opera Company's tribute to Canada's 150th celebrations.
 As a recitalist, he has performed for the Marilyn Horne Foundation, Aldeburgh Connection, Aldeburgh Festival, Musikverein, Wigmore Hall, Queen Elizabeth Hall, Morgan Library & Museum, Koerner Hall, Carnegie Hall, Saito Kinen Festival in Japan, Stratford Summer Music, British Broadcasting Corporation, and the Canadian Broadcasting Corporation.
 Westman first came to attention at the age of twelve when he was the first boy soprano to perform and record Mahler "4th Symphony" with Benjamin Zander and the Boston Philharmonic Orchestra in 1984.
 Westman is regularly featured as the Anthem singer for the Toronto Maple Leafs and numerous other NHL franchises.
 Four of Westman's recordings have been nominated for a Juno Award.
 Two recordings nominated for a Grammy Award.
Rose Bampton (November 28, 1907 in Lakewood, Ohio – August 21, 2007 in Bryn Mawr, Pennsylvania) was a celebrated American opera singer who had an active international career during the 1930s and 1940s.
 She began her professional career performing mostly minor roles from the mezzo-soprano repertoire in 1929 but later switched to singing primarily leading soprano roles in 1937 until her retirement from the opera stage in 1963.
Natalie Dessay (] ; born Nathalie Dessaix, 19 April 1965, in Lyon) is a French opera singer who had a highly acclaimed career as a coloratura soprano before leaving the opera stage on 15 October 2013.
 She dropped the silent "h" in her first name in honor of Natalie Wood when she was in grade school and subsequently simplified the spelling of her surname.
Virginia Zeani (born Virginia Zehan; 21 October 1925), Commendatore OMRI is a Romanian-born opera singer who sang leading soprano roles in the opera houses of Europe and North America.
 As a singer, she was known for her dramatic intensity and the beauty, wide range, and suppleness of her voice which allowed her to sing a repertoire of 69 roles ranging from the heroines in belcanto operas by Rossini and Donizetti to those of Wagner, Puccini and Verdi.
 She also created roles in several 20th-century operas, including Blanche in Poulenc's "Dialogues of the Carmelites".
 Zeani made her professional debut in 1948 as Violetta in "La traviata" which would become one of her signature roles.
 After her retirement from the stage in 1982, she became a well-known voice teacher.
 She was married to the Italian bass Nicola Rossi-Lemeni from 1957 until his death in 1991.
 A Distinguished Professor Emerita at Indiana University's Jacobs School of Music where she taught for many years, Zeani lives in Palm Beach County, Florida and has continued to teach singing privately.
Karel Kalaš (9 October 1910 – 3 May 2001) was a Czech operatic bass and film and television actor.
 He first rose to prominence at the Slovak National Theatre, where he was a member from 1934 through 1939.
 He left there to join the roster of principal singers at the National Theatre in Prague, where he worked until his retirement from the opera stage in 1972.
 He appeared in a handful of films and occasionally on Czech television during his career, notably winning acclaim for his portrayal of a retired opera singer in the 1978 film "Kulový blesk".
La Traviata is a 1983 Italian film written, designed, and directed by Franco Zeffirelli.
 It is based on the opera "La traviata" with music by Giuseppe Verdi and libretto by Francesco Maria Piave.
 Soprano Teresa Stratas, tenor Plácido Domingo, and baritone Cornell MacNeil starred in the movie, in addition to singing their roles.
 The film premiered in Italy in 1982 and went into general release there the following year.
 It opened in theatres in the U.S. on April 22, 1983.
 The movie's soundtrack with James Levine conducting the Metropolitan Opera Orchestra won a Grammy Award for Best Opera Recording.
Caterina Jarboro (July 24, 1898 – August 13, 1986) was an African-American opera singer.
 She was the first female black opera singer ever to sing on an opera stage in America, twenty-two years before Marian Anderson's début at the Metropolitan Opera.
Becoming Traviata is a 2012 French documentary film chronicling rehearsals of the Verdi opera "La traviata" at the Aix-en-Provence Festival.
 Directed by Philippe Béziat, the film focuses largely on stage director working with coloratura soprano Natalie Dessay.
 The film's French title is Traviata et nous ("Traviata and Us").