Question: How many decades did the company, which produced The Flintstones, dominate American television animation?
Context: Oskar Wilhelm Fischinger (22 June 1900 – 31 January 1967) was a German-American abstract animator, filmmaker, and painter, notable for creating abstract musical animation many decades before the appearance of computer graphics and music videos.  He created special effects for Fritz Lang's 1929 "Woman in the Moon", one of the first sci-fi rocket movies.  He made over 50 short films and painted around 800 canvases, many of which are in museums, galleries, and collections worldwide.  He invented the Lumigraph device, that produces color displays with hand movements.  Among his film works is "Motion Painting No. 1" (1947), which is now listed on the National Film Registry of the U.S. Library of Congress. Star vs. the Forces of Evil is an American animated television series produced by Disney Television Animation.  The first episode was shown on January 18, 2015, on Disney Channel as a special preview, and the series officially premiered on March 30, 2015, on Disney XD.  The show was created by Daron Nefcy, who had worked on storyboards for "Wander Over Yonder" and "Robot and Monster".  Nefcy became the second woman to create an animated series for Disney Television Animation (the first being Sue Rose, who created "Pepper Ann"), and the first woman to create a Disney XD series.  On February 12, 2015, Disney renewed the series for a second season prior to its premiere on Disney XD.  The second season premiered on July 11, 2016.  On March 4, 2016, it was renewed for a third season, with a two-hour TV movie called "The Battle for Mewni", which aired on July 15, 2017.  On February 28, 2017, it was officially renewed for a fourth season. Hanna-Barbera Productions, Inc. (simply known as Hanna-Barbera and also referred to as H-B Enterprises, H-B Production Company and Hanna-Barbera Cartoons, Inc.) was an American animation studio that dominated American television animation for over three decades in the mid 20th century. Wesley Meyer "Wes" Archer (born November 26, 1961) is an American television animation director.  He was one of the original three animators (along with David Silverman and Bill Kopp) on "The Simpsons", Tracey Ullman shorts, and subsequently directed a number of "The Simpsons" episodes (many of which had John Swartzwelder as an episode writer) before becoming supervising director at "King of the Hill."  A few years later he left "King of the Hill" to direct for "Futurama", before eventually returning to "King of the Hill".  Wes continued to supervise the direction of "King of the Hill" until the final season.  He acted as a consulting director for the last season of "King of the Hill", as he joined "The Goode Family" as supervising director.  Archer's college animation film, "Jac Mac and Rad Boy, Go! " has long been a cult classic after receiving repeated airplay on USA Network's "Night Flight" in the 1980s.  He studied at the Film Graphics/Experimental Animation Program at CalArts.  He is currently the supervising director on "Rick and Morty". Recess: School's Out is a 2001 American animated comedy film based on the Disney television series "Recess".  It was produced by Walt Disney Pictures, Walt Disney Television Animation and Walt Disney Television Animation Digital Production with animation done by Sunwoo Animation and Sunwoo Digital International.  The film was distributed by Buena Vista Pictures Distribution, and released theatrically in the United States on February 16, 2001. The Flintstones is an American animated sitcom produced by Hanna-Barbera for ABC.  The series takes place in a romanticized Stone Age setting, depicts the lives of the titular characters and their next-door neighbors and best friends.  It was originally broadcast from September 30, 1960, to April 1, 1966 in a prime time schedule, the first such example of an animated series. Rubin Schron, who goes by Ruby, is a New York City real estate investor, landlord and the founder of Cammeby's International Group.  He has a personal net worth of well over $10 billion, according to data company Real Capital Analytics.  The portfolio of Cammeby's, which Schron founded in 1967, includes office buildings, market-rate and government-subsidized apartment complexes, nursing homes, the 16-building complex in Sunset Park now known as Industry City, a stake in the bottom half of Woolworth Building and industrial properties scattered across Long Island.  In 2013, Schron made an unsolicited and unsuccessful offer to buy the Empire State Building for $2 billion, but he has not had problems closing many other deals throughout his long career.  In 2003, an investment group led by Schron paid $600 million for a portfolio of about 6,000 outer-borough apartments from Donald Trump.  Other buildings he owns include the Monterey, a 521-unit rental multifamily building on Manhattan's Upper East Side; over the decades, Schron has also amassed a portfolio of Mitchell-Lama apartment buildings whose values have been skyrocketing to record values, after reverting to market rates when government subsidies expired.  In 2007, he sold nearly 4,000 units of former Mitchell-Lama properties in five complexes in Harlem and on Roosevelt Island for $940 million.  Schron, who practices Orthodox Judaism, has eight children and 50 grandchildren.  He and his family have lived in the same single-family home in Brooklyn for many decades. Disney's House of Mouse is an American animated television series, produced by Walt Disney Television Animation (now Disney Television Animation), that originally aired from 2001 to 2003.  On September 2, 2002, an all night marathon of this show titled "Night of 1000 Toons" aired on Toon Disney.  "Disney's House of Mouse" is a spin-off of the popular short-lived Disney series "Mickey Mouse Works", and featured many Mouse Works shorts as well as new shorts created specifically for the spin-off series. Jean Vander Pyl (October 11, 1919 – April 10, 1999) was an American actress on radio, television and movies.  Although her career spanned many decades, she is perhaps best remembered as the voice of Wilma Flintstone for the Hanna-Barbera cartoon "The Flintstones".  In addition to Wilma Flintstone, she also provided the voices of Pebbles Flintstone, Rosie the robot maid on the animated series "The Jetsons", Goldie, Lola Glamour, Nurse LaRue and other characters in "Top Cat", Winsome Witch on "The Secret Squirrel Show" and Ogee on "The Magilla Gorilla Show". Mickey's House of Villains (also known as House of Mouse: The Villains) is a 2002 direct-to-video animated film produced by The Walt Disney Company (Walt Disney Television Animation and Toon City Animation, with animation coordination by Walt Disney Feature Animation Florida.  It is based on the Disney Channel animated television series "Disney's House of Mouse" and a sequel to the direct-to-video animated film "", starring Mickey Mouse, Donald Duck, Minnie Mouse, Goofy, Daisy Duck and Disney Villains that have appeared in past Disney productions.  It was released on both VHS and DVD by Walt Disney Home Video on September 3, 2002.  It was followed by a 2004 direct-to-video animated film, "", produced by DisneyToon Studios, on August 17, 2004.
Answer: three