Question: What was the population at the 2010 census of the incorporated village all of which is served by the East Williston Union Free School District?

full_context: Document 1: East Rockaway, New York: East Rockaway is a village in Nassau County, New York, in the United States. The population was 9,818 at the 2010 census.
Document 2: Hauppauge Union Free School District: Hauppauge Union Free School District is a school district based in Hauppauge, New York. It is near the Commack School District and Half Hollow Hills Central School District, as well as the Syosset Central School District and Jericho Union Free School District in Nassau County
Document 3: Hewlett-Woodmere School District: The Hewlett-Woodmere Public School District, Union Free School District 14, is located in the southwest section of Nassau County, New York and borders the New York City borough of Queens. Communities in the district include, in full or in part, Hewlett, Woodmere, Woodsburgh, North Woodmere an unincorporated area of Valley Stream, the Gibson section of Valley Stream, Hewlett Harbor, Hewlett Neck, and Hewlett Bay Park, as well as parts of Lynbrook, all comprise the geographical boundaries for the school district. There are approximately 3,200 students enrolled in pre-K through 12th grade. The district is operated under the supervision of a seven-member Board of Education.
Document 4: Village of the Branch, New York: Village of the Branch is a village in the Town of Smithtown in Suffolk County, New York, United States. The population was 1,807 at the 2010 census. The village incorporated in 1927.
Document 5: The Wheatley School: The Wheatley School is a public high school serving grades 8 through 12 located in Old Westbury, Long Island, New York and part of the East Williston Union Free School District. The school district encompasses all of East Williston and parts of Mineola, Albertson, Old Westbury, and Roslyn Heights.
Document 6: Levittown, New York: Levittown, formerly Island Trees, is a hamlet and census-designated place (CDP) in the Town of Hempstead in Nassau County, New York on Long Island. It is located half way between the villages of Hempstead and Farmingdale. As of the 2010 census, the CDP had a total population of 51,881, making it the most populated CDP in Nassau County and the second most populated CDP on Long Island, behind only Brentwood.
Document 7: East Massapequa, New York: East Massapequa is a hamlet and census-designated place (CDP) located within the Town of Oyster Bay in Nassau County, New York, in the New York City Metropolitan Area United States. The population was 19,069 at the 2010 census. The hamlet lies in New York's 3rd congressional district. The most eastern third portion of East Massapequa (within the Amityville School District) was previously the hamlet of West Amityville and started utilizing a Massapequa mailing address in 1975. Former NBA point guard A.J. Price grew up in East Massapequa and attended Amityville Memorial High School, as did rapper Posdnous from the legendary hip hop group De La Soul.
Document 8: Sea Cliff, New York: The Incorporated Village of Sea Cliff is a village located within the Town of Oyster Bay in Nassau County, New York. According to the United States 2010 Census, the village population was 4,995. The village is part of the North Shore School District.
Document 9: East Rockaway High School: East Rockaway Junior-Senior High School (often abbreviated ERHS) is a co-educational six-year secondary school in East Rockaway, New York, and the sole high school in Nassau County, New York, School District 41 (East Rockaway School District), the smallest school district in Nassau County. It is currently undergoing renovations to expand the school into a middle school and high school, becoming a seven-year secondary school. East Rockaway High School serves graduates from local Centre Ave. and Rhame Ave. Elementary Schools, as well as the private St. Raymond Elementary School.
Document 10: East Williston Union Free School District: The East Williston Union Free School District is a school district that serves all of East Williston and parts of Roslyn Heights, Albertson, Mineola, and Old Westbury in central Nassau County, New York.
Document 11: Old Westbury, New York: Old Westbury is a village in Nassau County, in the U.S. state of New York, on the North Shore of Long Island. As of the 2010 United States Census, the village population was 4,671.
Document 12: Island Trees Union Free School District: Island Trees Union Free School District is a school district in central Nassau County on Long Island, approximately 31 miles east of New York City. The district includes parts of the following hamlets; Levittown, Bethpage and Seaford.
Document 13: Nassau County, New York: Nassau County is a suburban county on the western side of Long Island in the U.S. state of New York. At the 2010 census, the county's population was 1,339,532, estimated to have increased to 1,361,500 in 2016. The county seat is in the Village of Garden City, within the boundaries of the Mineola 11501 zip code.
Document 14: East Williston, New York: East Williston is an incorporated village in Nassau County, New York in the United States. The population was 2,556 at the 2010 census.
Document 15: Herricks Union Free School District: The Herricks Union Free School District is a school district located in western Nassau County on Long Island, in New York State. The district lies within the Greater New Hyde Park area and serves a number of communities including Herricks, Garden City Park, Manhasset Hills, Searingtown, North Hills, Williston Park and Albertson.
ground_truth: 2,556