Question: How many years has the Mona Lisa survived?
About the article "Mona Lisa", section "Conservation".

Candidate passages:
"The Ballad of Mona Lisa" (commonly referred to as simply "Mona Lisa") is a song by American rock band Panic!
at the Disco, released February 1, 2011 as the first single from the group's third studio album, "Vices & Virtues" (2011).
Vocalist Brendon Urie wrote the song to express personal struggles and convictions many years prior to its official production for "Vices & Virtues".
The song has received positive critical reviews upon its release. 
The "Mona Lisa" has survived for more than 500 years, and an international commission convened in 1952 noted that "the picture is in a remarkable state of preservation."
This is partly due to the result of a variety of conservation treatments the painting has undergone.
A detailed analysis in 1933 by Madame de Gironde revealed that earlier restorers had "acted with a great deal of restraint."
Nevertheless, applications of varnish made to the painting had darkened even by the end of the 16th century, and an aggressive 1809 cleaning and revarnishing removed some of the uppermost portion of the paint layer, resulting in a washed-out appearance to the face of the figure.
Despite the treatments, the "Mona Lisa" has been well cared for throughout its history, and although the panel's warping caused the curators "some worry", the 2004–05 conservation team was optimistic about the future of the work.
The "Isleworth Mona Lisa" is wider than the "Mona Lisa" in the Louvre, having columns on either side which also appear in some other versions.
The Louvre painting merely has the projecting bases of columns on either side, suggesting that the picture was originally framed by columns but was trimmed.
However, experts who examined the "Mona Lisa" in 2004–2005 stated that the original painting had not been trimmed.
The figure of the "Isleworth Mona Lisa" closely resembles that of the "Mona Lisa", being identically composed and lit.
However, the face of the "Isleworth Mona Lisa" appears younger, leading to speculation that it is an earlier version by the artist.
According to Pulitzer, multiple art experts agreed that the neck of the "Isleworth Mona Lisa" is inferior to the necks of other Leonardo subjects, suggesting that somebody else touched up the neck.
Several people Pulitzer consulted believed that the hands and face of the portrait were by Leonardo, but the rest may have been finished by another or others.
The background in the Isleworth painting is considerably less detailed than the background in the Louvre painting, causing many art experts cited in Pulitzer's book to suggest that if Leonardo did indeed paint the subject, it is likely somebody else painted the background. 
Marcel Duchamp, among the most influential artists of his generation, in 1919 may have inadvertently set the standard for modern manifestations of "Mona Lisa" simply by adding a goatee to an existing postcard print of Leonardo's original.
Duchamp pioneered the concept of "readymades", which involves taking mundane objects not generally considered to be art and transforming them artistically, sometimes by simply renaming them and placing them in a gallery setting.
In "L.H.O.O.Q."
the "found object" is a "Mona Lisa" postcard onto which Duchamp drew a goatee in pencil and appended the title.
The title, Duchamp is said to have admitted in his later years, is a pun.
The letters L-H-O-O-Q pronounced in French form the sentence "Elle a chaud au cul", colloquially translating into English as "She has a hot ass.
"As was the case with many of his readymades, Duchamp made multiple versions of "L.H.O.O.Q."
in varying sizes and media throughout his career.
An unmodified black and white reproduction of "Mona Lisa" on a playing-card, onto which Duchamp in 1965 inscribed "LHOOQ rasée" ("LHOOQ Shaved"), is among many "second-generation" variants referencing the original "L.H.O.O.Q".
Duchamp's parody of "Mona Lisa" was itself parodied by Francis Picabia in 1942, annotated "Tableau Dada Par Marcel Duchamp" ("Dadaist Scene for Marcel Duchamp"), another example of "second-generation" interpretations of "Mona Lisa".
Salvador Dalí created his "Self Portrait as Mona Lisa" in 1954, referencing "L.H.O.O.Q."
in collaboration with Philippe Halsman, incorporating his photographs of a wild-eyed Dalí showing his handlebar moustache and a handful of coins.
In 1958, Icelandic painter Erró then incorporated Dalí's version into a composition which also included a film-still from Dalí's "Un Chien Andalou".
Fernand Léger and René Magritte are among the numbers of Modern art masters who've adapted "Mona Lisa" using their own iconography.
None of the parodies have tarnished "Mona Lisa"'s image; rather, they reinforce her fame.
Duchamp's "mustached" "Mona Lisa" embellishment continues to inspire imitation.
Contemporary conceptual artist Subodh Gupta gave "L.H.O.O.Q."
three-dimensional form in his 2009 bronze sculpture "Et tu, Duchamp?".
Gupta, from India, considers himself an "idol thief" and has reinterpreted a number of iconic works from European art history. 
 and the Isleworth Mona Lisa.
Shortly before World War I, Hugh Blaker discovered a painting of the Mona Lisa in the home of a Somerset nobleman in whose family it had been for nearly 100 years.
This discovery led to the conjecture that Leonardo painted two portraits of Lisa del Giocondo: the famous one in The Louvre, and the one discovered by Blaker, who bought the painting and took it to his studio in Isleworth, London, from which it takes its name.
According to Encyclopedia Americana and The New York Times, The Isleworth Mona Lisa has been attributed to Leonardo, and is thought to be the unfinished portrait from which Raphael made his famous sketch (which is in the Louvre museum), and is in no sense a copy of the Louvre Mona Lisa.