The Grand Prix of Houston, an annual auto race on the IndyCar Series circuit was held on a 1.7-mile temporary street circuit in NRG Park. The October 2013 event was held using a tweaked version of the 2006–2007 course. The event had a 5-year race contract through 2017 with IndyCar. In motorcycling, the Astrodome hosted an AMA Supercross Championship round from 1974 to 2003 and the NRG Stadium since 2003. Houston is also one of the first cities in the world to have a major eSports team represent it, in the form of the Houston Outlaws. The Outlaws play in the Overwatch League and are one of two Texan teams, the other being the Dallas Fuel. Houston is also one of eight cities to have an XFL team, the Houston Roughnecks. The city of Houston has a strong mayoral form of municipal government. Houston is a home rule city and all municipal elections in the Texas are nonpartisan. The city's elected officials are the mayor, city controller and 16 members of the Houston City Council. The current mayor of Houston is Sylvester Turner, a Democrat elected on a nonpartisan ballot. Houston's mayor serves as the city's chief administrator, executive officer, and official representative, and is responsible for the general management of the city and for seeing that all laws and ordinances are enforced. The original city council line-up of 14 members (nine district-based and five at-large positions) was based on a U.S. Justice Department mandate which took effect in 1979. At-large council members represent the entire city. Under the city charter, once the population in the city limits exceeded 2.1 million residents, two additional districts were to be added. The city of Houston's official 2010 census count was 600 shy of the required number; however, as the city was expected to grow beyond 2.1 million shortly thereafter, the two additional districts were added for, and the positions filled during, the August 2011 elections. The city controller is elected independently of the mayor and council. The controller's duties are to certify available funds prior to committing such funds and processing disbursements. The city's fiscal year begins on July 1 and ends on June 30. Chris Brown is the city controller, serving his first term . As the result of a 2015 referendum in Houston, a mayor is elected for a four-year term, and can be elected to as many as two consecutive terms. The term limits were spearheaded in 1991 by conservative political activist Clymer Wright. During 1991–2015, the city controller and city council members were subjected to a two-year, three-term limitation – the 2015 referendum amended term limits to two four-year terms. some councilmembers who served two terms and won a final term will have served eight years in office, whereas a freshman councilmember who won a position in 2013 can serve up to two additional terms under the previous term limit law – a select few will have at least 10 years of incumbency once their term expires.