Question: When was the soundtrack of the spin-off, sequel to the "Rocky" film series released?

Context paragraphs:
Rocky (film series): Rocky is a series of boxing films based on the eponymous, fictional character Rocky Balboa, played in each film by Sylvester Stallone.  The films by order of release date are: "Rocky" (1976), "Rocky II" (1979), "Rocky III" (1982), "Rocky IV" (1985), "Rocky V" (1990), "Rocky Balboa" (2006) and "Creed" (2015).  The film series has grossed more than $1.4 billion at the worldwide box office.

Nation and Destiny: Nation and Destiny (Chosŏn'gŭl: 민족과 운명 ; MR: "Minjokgwa ummyeong " ) is a 62-part North Korean film series released between 1992 and 2002.  It aims to show that the Korean people "can live a glorious life only in the bosom of the Great Leader and socialist fatherland".  Kim Jong-Il personally chose the title and was extensively involved in the early episodes.  Conceived as the largest film series ever produced in any country, it was the largest investment ever made in the history of North Korean cinema.  Initially, the most senior writers, directors and actors were involved in the project and it was heavily promoted and eulogized by the North Korean media.  The series was projected to reach 100 episodes, but none have been released since 2002.

The Grudge (film series): The Grudge is an American horror film series released by Sony Pictures, based on the Japanese "Ju-on" films.  The first installment is a remake of "" and follows a similar storyline to the Japanese film.  The sequel, "The Grudge 2", is not a remake and follows a unique storyline, albeit still drawing inspiration from several "Ju-on" films.  The most recent sequel, "The Grudge 3", picks up shortly after the events of the second film.

Dick Tracy's Dilemma: Dick Tracy's Dilemma, released in the United Kingdom as Mark of the Claw, is a 1947 American pulp action film based on the 1930s comic strip character of the same name created by Chester Gould.  Ralph Byrd stars as Dick Tracy, reprising the role after Republic Pictures's 1937 "Dick Tracy" serial and its three sequels.  The film is the third installment of the "Dick Tracy" film series released by RKO Radio Pictures.

Bombaiyer Bombete (film): Bombaiyer Bombete (Bengali: বোম্বাইয়ের বোম্বে ) is a 2003 Indian Bengali thriller film directed by Sandip Ray based on the story of the same name by Satyajit Ray.  It was the third big screen adaptation of the fictional detective character Feluda after 25 years of the second Feluda movie "Joi Baba Felunath" (1979), directed by his (Sandip Ray) father Satyajit Ray.  It was the first big screen adaptation of the Feluda new film series (Continuation of the original series) though Sabyasachi played Feluda in all the ten TV films of Feluda TV film series (1996-2000) directed by Sandip Ray.  The movie was a sequel to the Feluda TV film series (1996-2000) which was a sequel to the Satyajit Ray's Feluda film series (1974-1979).  Previously Feluda was played by Soumitra Chatterjee in two films "Sonar Kella" (1974) and "Joi Baba Felunath" (1979), directed by Satyajit Ray.  First of the Feluda TV film series, "Baksho Rahashya" (1996) in which Sabyasachi Chakrabarty starred as Feluda for the first time, was released in theaters before releasing this movie in 2001.  "Bombaiyer Bombete" was the eleventh film of Sabyasachi Chakrabarty as Feluda.  After the huge success of "Bombaiyer Bombete" four sequels have been made till 2011.  They are "Kailashey Kelenkari" (2007), "Tintorettor Jishu" (2008), "Gorosthaney Sabdhan" (2010) and "Royal Bengal Rohosso" (2011).  A fifth sequel is announced by Sandip Ray where Sabyasachi Chakrabarty will return as the Bengali sleuth Feluda after five years and the film is named "Double Feluda" which is heading to release in 2016.

Lilla Jönssonligan: Lilla Jönssonligan (English: The Little Jönssonleague ) is a Swedish film series that consists of four movies.  The film series is a spin-off of the original "Jönssonligan" film series.  The main difference about the two series is that the main characters are portrayed as kids instead of adults in this one, hence the word "little" in the title.  Rocky, the original third member, is not featured in any of the films.  Unlike the "adult Jönssonligan", where the gang where bumbling anti-heroes, the "litte Jönssonligan" is often straight up heroic.

Dark Delusion: Dark Delusion (1947) is an American film, released by Metro-Goldwyn-Mayer, and starring James Craig, Lionel Barrymore, and Lucille Bremer.  The film was the last in the Dr. Kildare film series released by MGM.

He's Back (The Man Behind the Mask): "He's Back (The Man Behind the Mask)" is a song by American shock rock musician Alice Cooper.  It was released as the lead single from his 1986 album "Constrictor", and the theme song of "", a slasher film and sixth part of the "Friday the 13th" film series released in the same year.  The song is heard various times throughout the film and in the end credits.  Two other songs, "Teenage Frankenstein" (also from "Constrictor") and "Hard Rock Summer" (which remained commercially unreleased until 1999) are also featured in the film.

Creed (soundtrack): Creed: Original Motion Picture Soundtrack is a soundtrack album for the 2015 film "Creed", which features music by various artists.  The album was released on November 20, 2015 through Atlantic Records.

Creed (film): Creed is a 2015 American sports drama film directed by Ryan Coogler and written by Coogler and Aaron Covington.  A spin-off and sequel to the "Rocky" film series, the film stars Michael B. Jordan as Adonis Johnson Creed, Apollo Creed's son, with Sylvester Stallone reprising the role of Rocky Balboa.  It also features Tessa Thompson, Phylicia Rashād, Tony Bellew and Graham McTavish.  The film reunites Jordan with "Fruitvale Station" writer/director Coogler, as well as Wood Harris, with whom Jordan had worked on "The Wire".

Supporting paragraphs: Creed (soundtrack) Creed (film)
Answer: 2015