Question: The winners of the Norwegian Melodi Grand Prix Junior 2012 are how old?

Context paragraphs:
Melodi Grand Prix Junior 2011: The Melodi Grand Prix Junior 2011 was Norway's tenth national Melodi Grand Prix Junior for young singers aged 8 to 15.  It was held in Oslo Spektrum, Oslo, Norway and broadcast live Norwegian Broadcasting Corporation (NRK).

Melodi Grand Prix Junior 2002: Melodi Grand Prix Junior 2002 was the first ever music competition in Norway in the series "Melodi Grand Prix Junior" for children aged 9 and 15 years.  The winners were To små karer (meaning two little guys) with the song "Paybacktime".  They represented Norway in MGP Nordic (Melodi Grand Prix Nordic 2002) held in Denmark together with the second-placed Wicked Instinct and third-placed Black Jackets.  Program presenter was Thomas Numme, while Stian Barsnes Simonsen was backstage.

Melodi Grand Prix Junior 2012: The Melodi Grand Prix Junior 2012 was Norway's eleventh national Melodi Grand Prix Junior for young singers aged 8 to 15.  It was held in Oslo Spektrum, Oslo, Norway and broadcast live Norwegian Broadcasting Corporation (NRK).  It was hosted by Margrethe Røed and Tooji, the winner of Norwegian Melodi Grand Prix 2012.

Melodi Grand Prix Junior 2010: The Melodi Grand Prix Junior 2010 was Norway's ninth national Melodi Grand Prix Junior for young singers aged 8 to 15.  It was held in Oslo Spektrum, Oslo, Norway and broadcast live Norwegian Broadcasting Corporation (NRK).

Marcus &amp; Martinus: Marcus & Martinus, sometimes known as M&M, is a Norwegian pop duo composed of twin brothers Marcus Gunnarsen and Martinus Gunnarsen (born 21 February 2002) from Trofors.  They are both 15 years old, and have released three albums.

Melodi Grand Prix: Melodi Grand Prix, sometimes as Norwegian Melodi Grand Prix (Norwegian: "Norsk Melodi Grand Prix"), commonly known as Grand Prix and MGP, is an annual music competition organised by Norwegian public broadcaster Norsk Rikskringkasting (NRK).  It determines the country's representative for the Eurovision Song Contest, and has been staged almost every year since 1960.

Hei (album): Hei is the debut album of the Norwegian child duo Marcus & Martinus, winners of the Norwegian Melodi Grand Prix Junior 2012.  The album released on Sony Music Entertainment on 23 February 2015 and was successful, peaking at number 2 on the Norwegian Albums Chart.  A special follow-up album was released nine months later on 6 November 2015 also on Sony including additional tracks.  The special edition was titled "Hei – Fan-Spesial".

Melodi Grand Prix Junior 2009: The Melodi Grand Prix Junior 2009 was Norway's eighth national Melodi Grand Prix Junior for young singers aged 8 to 15.  It was held in Oslo Spektrum, Oslo, Norway and broadcast live Norwegian Broadcasting Corporation (NRK) on 5 September 2008 at the Oslo Spektrum.

Melodi Grand Prix Junior 2013: The Melodi Grand Prix Junior 2013 was Norway's twelfth national Melodi Grand Prix Junior for young singers aged 8 to 15.  It was held in Oslo Spektrum, Oslo, Norway and was hosted by Tooji and Margrethe Røed.  The show was broadcast live Norwegian Broadcasting Corporation (NRK).

Melodi Grand Prix Junior 2008: The Melodi Grand Prix Junior 2008 was Norway's seventh national Melodi Grand Prix Junior for young singers aged 8 to 15.  It was held on June 2, 2007, in Oslo Spektrum, Oslo, Norway and broadcast live Norwegian Broadcasting Corporation (NRK) on 5 September 2008 at the Oslo Spektrum.

Supporting paragraphs: Hei (album) Marcus &amp; Martinus
Answer: 15 years