Question: In what year did Leroy Sievers begin serving as the executive producer "Nightline"?

Context articles: Dete Meserve
Abby Lee Miller
Ted Koppel
SkyGreece Airlines destinations
Joe Simitian
Elizabeth Smart kidnapping
Leroy Sievers
John R. Montgomery
Nørrebro station
Brad Kern

Dete Meserve is an award-winning and bestselling author as well as film and television executive and a principal of Wind Dancer Films.
 Wind Dancer Films is best known as the creators and producers of Home Improvement starring Tim Allen, What Women Want starring Helen Hunt and Mel Gibson, Where The Heart Is starring Natalie Portman.
 Meserve's credits include producing Bernie starring Jack Black, Shirley MacLaine and Matthew McConaughey, executive producer of Walker Payne starring Sam Shepard and Jason Patric, executive producer of the TV series Wildest Africa for Discovery International, executive producer of As Cool As I Am, starring Claire Danes and James Marsden.
 In 2014, she was an executive producer of the George Lopez sitcom, "Saint George," and producer of the thriller, The Keeping Room starring Sam Worthington, Hailee Steinfeld and Brit Marling.
 She is currently an Executive Producer of the hit kids television series Ready Jet Go on PBSKids.
Abigale Lee Miller (born September 21, 1966) is an American dance instructor, choreographer, and the director and owner of Reign Dance Productions.
 She was also the founder of the Abby Lee Dance Company and appeared on the reality television series "Dance Moms".
 In June 2016, she pled guilty to felony bankruptcy fraud and was sentenced in May 2017 to one year and a day in federal prison.
 On July 12, 2017, Miller reported to the Victorville Federal Correctional Institution in Victorville, California, to begin serving her prison term.
Edward James Martin "Ted" Koppel (born February 8, 1940) is a British-born American broadcast journalist, best known as the anchor for "Nightline", from the program's inception in 1980 until 2005.
SkyGreece Airlines operated scheduled flights from Greece to Montreal and Toronto.
 It planned to begin serving New York City soon, Chicago and South Africa.
Saren Joseph Simitian (born February 1, 1953) is a California Democratic politician.
 From 2004 to 2012, he was the State Senator representing California's 11th State Senate district, which encompasses all or part of 13 cities in San Mateo, Santa Clara, and Santa Cruz counties.
 Approaching his term limit at the end of 2012, he ran for and was elected as a Santa Clara County Supervisor, to begin serving in 2013.
Elizabeth Smart was abducted at the age of fourteen from her bedroom in Salt Lake City, Utah on June 5, 2002.
 She was rescued by police officers nine months later on March 12, 2003, in Sandy, Utah, about 18 miles from her home, in the captivity of Brian David Mitchell and Wanda Ileen Barzee, who were indicted for her kidnapping, but initially ruled unfit to stand trial.
 After both defendants were found competent to stand trial, Barzee was convicted in 2009 and Mitchell was convicted in 2010.
 Mitchell was held in the Salt Lake County Jail following his sentencing on May 25, 2011.
 On August 31, he was transferred to a federal prison in Arizona to begin serving a life sentence for his crimes.
 The abduction of Elizabeth and her rescue were widely reported and were the subject of a made-for-television movie and a published book.
Leroy Sievers (June 16, 1955 – August 15, 2008) was a journalist who won 12 national news Emmy Awards, two Peabody Awards, and two Alfred I. duPont-Columbia University Awards.
 He was a commentator for National Public Radio, served as a bureau chief for CBS news, served as an executive producer for the ABC program "Nightline", and covered a variety of global conflicts as a war correspondent.
 Sievers was also part of the Discovery Channel program entitled "Living with Cancer", hosted by his friend Ted Koppel.
 This show was taped at the Discovery Channel Headquarters in Silver Spring, Maryland on May 6, 2007, and featured other cancer survivors, including Elizabeth Edwards and Lance Armstrong.
John R. Montgomery IV is a television producer and advertising industry veteran.
 Currently, he serves as an Executive Producer for the CBS series "Superior Donuts".
 Previously, he was an Executive Producer on the CW reboot of "MADtv" and the Creator/Executive Producer of the web series "Attention Deficit Theater", which made its debut at SXSW and is available on CW Seed.
 In addition, Montgomery was an Executive Producer on CBS' "The Crazy Ones".
 There, he also received the unique credit: "Suggested by the Experiences of" as the series was based in part on Montgomery's 33-year career at the Leo Burnett advertising agency in Chicago.
 Show creator David E. Kelley cited Montgomery as the inspiration for the "The Crazy Ones" and character Simon Roberts, portrayed by Robin Williams.
Nørrebro station is a railway station on the S-train’s Ring line in Copenhagen, Denmark.
 It serves the outer end of the Nørrebro district.
 The planned City Circle Line would see underground trains of the Copenhagen Metro begin serving the station as well.
Brad Kern is an American television producer and writer.
 He has been Executive Producer/Showrunner of CBS TV's hit, "" since midway through season two.
 Previously, he served as Executive Producer/Showrunner on CW's supernatural, "Beauty and the Beast" for three seasons; and, prior to that, Executive Producer of the FOX action adventure, "Human Target".
 He was also Executive Producer/Showrunner on the hit supernatural drama "Charmed" for all eight seasons.
 Before that, he was Executive Producer/Showrunner of the award-winning Fox series "New York Undercover".
 Other previous credits include Co-Executive Producer on "", Supervising Producer on "The Adventures of Brisco County, Jr.", and Executive Story Editor on "Hill Street Blues".