Question: Highest Duty: My Search for What Really Matters is a memoir written by a pilot who retired after how many years of commercial service?

Context paragraphs:
Nothing Really Matters: "Nothing Really Matters" is a song recorded by American singer Madonna for her seventh studio album, "Ray of Light" (1998).  It was written by Madonna and Patrick Leonard, and was produced by the singer with William Orbit and Marius De Vries.  The song was released as the fifth and final single from the album on March 2, 1999 by Maverick Records and Warner Bros.  Records.  An EDM track on which Madonna experiments with different musical genres, "Nothing Really Matters" includes ambient music and electronic noise frequencies that were added by De Vries.  Lyrically, the recording delves on the singer's first daughter Lourdes Leon, having also themes of selfishness, affection, and motherhood.

Inbox by Gmail: Inbox by Gmail is an email service developed by Google.  Announced in limited invitation-only basis on October 22, 2014, it was officially released to the public on May 28, 2015.  Made by the same people who work on Gmail, Inbox serves as a "completely different type of inbox, designed to focus on what really matters."

G-A-Y: G-A-Y is a gay nightclub in London.  It operated from the London Astoria music venue for 15 years until July 2008.  The Boston Globe described it as "London's largest gay-themed club night", "NME" reported that it "attracts 6,000 clubbers each week", and "The Independent" described it as "the one London gig that really matters" for "today's pop stars".  On Friday 3 October 2008, it moved to famous gay venue Heaven.

Goodbye, Antoura: Goodbye, Antoura: A Memoir of the Armenian Genocide is a memoir written by Karnig Panian, and published in English by the Stanford University Press in 2015.  The memoir, originally written in Armenian, follows the five-year old Karnig Panian through the years of the Armenian Genocide, through Anatolia and Syria, and finally to the College St. Joseph in Antoura, Lebanon, where the Ottoman Government had established an orphanage to Turkify surviving Armenian and Kurdish children.

Chesley Sullenberger: Chesley Burnett "Sully" Sullenberger III (born 1951) is an American retired airline captain celebrated for the January 15, 2009 water landing of US Airways Flight 1549 in the Hudson River off Manhattan after the plane was disabled by striking a flock of Canada geese immediately after takeoff; all 155 people aboard survived.  Sullenberger is an international speaker on airline safety and has helped develop new protocols for airline safety.  He served as the co-chairman, along with First Officer Jeffrey Skiles, of the EAA's Young Eagles youth introduction-to-aviation program from 2009 to 2013.  He retired from US Airways after 30 years as a commercial pilot on March 3, 2010.  In May of the following year, Sullenberger was hired by CBS News as an Aviation and Safety Expert.

Disco Bloodbath: Disco Bloodbath: A Fabulous but True Tale of Murder in Clubland is a 1999 memoir written by James St. James about his life as a Manhattan celebutante and club kid.  The book specifically chronicles his friend Michael Alig's rise to fame, and Alig and his roommate's subsequent murder of fellow club kid and drug dealer Andre "Angel" Melendez.  St. James was Alig's mentor, rival, and collaborator in the Manhattan party scene, and was familiar with many of its key figures.  The memoir was later retitled "Party Monster", after the 2003 motion picture of that name starring Macaulay Culkin, Seth Green, Chloë Sevigny, and Marilyn Manson.

Nothing Really Matters (Mr Probz song): "Nothing Really Matters" is a song by Dutch recording artist Mr Probz.  It was released on 29 September 2014 as a digital download.  The song was written by Dennis Princewell Stehr, Aliaune Thiam, Giorgio Tuinfort and Jake Gosling.  It peaked to number 1 on the Dutch Singles Chart and in Portugal.  The song has also charted in Belgium and Sweden.

Andreas Bruce: Ferdinand "Andreas" Edvard Bruce, born as Christina "Therese" Isabelle Jeanette Louise Bruce (1808–1885) was a Swedish memoir writer.  His story was the first memoir written by a transsexual person in Sweden and is regarded as unique in many aspects.

Highest Duty: My Search for What Really Matters: Highest Duty: My Search for What Really Matters is a memoir written by Chesley Sullenberger and Jeffrey Zaslow (1958–2012) describing the events of US Airways Flight 1549.  The "New York Times" bestselling autobiography of Capt. Chesley “Sully” Sullenberger—the pilot who landed a crippled airplane in New York's Hudson River, saving the lives of the 155 passengers—discusses leadership, responsibility, and service, along with his life story.

Law enforcement in Cuba: Law enforcement in Cuba is the responsibility of the National Revolutionary Police Force (Spanish: "Policía Nacional Revolucionaria" , PNR) under the administration of the Cuban Ministry of the Interior.  Article 64 of the Cuban Constitution states that "Defense of the socialist motherland is every Cuban's greatest honor and highest duty."  Conscription into either the armed forces or the national police force is compulsory for those over the age of 16.  Nevertheless, conscripts have no choice to which service they are assigned.

Supporting paragraphs: Highest Duty: My Search for What Really Matters Chesley Sullenberger
Answer: 30