every 100 females there were 104.3 males. For every 100 females age 18 and over, there were 101.3 males. The median income for a household in the CDP was $46,763, and the median income for a family was $51,801. Males had a median income of $29,607 versus $23,716 for females. The per capita income for the CDP was $17,220. 11.7% of the population and 8.9% of families were below the poverty line. Out of the total population, 15.0% of those under the age of 18 and 9.0% of those 65 and older were living below the poverty line. Government and infrastructure The United States Postal Service operates the Waialua Post Office at 67-079 Nauahi Street. The postal code is 96791. In 2017, the state approved NRG Energy, Inc., to build a 49 megawatt solar farm project near Waialua called Kawailoa Solar. HECO will buy electricity from this solar farm at 11 cents per kilowatt-hour (kWh) for 22 years. On September 10, 2019, the 49 megawatt Kawailoa Solar developed by Clearway Energy Group began its operation. Originally started by the developer SunEdison, Hawaiian Electric broke its ties to the firm in February 2016 before SunEdison's bankruptcy proceedings. San Francisco-based Clearway's predecessor, NRG Energy's Community Solar division, took over the project at the end of November 2016. On January 22, 2019, the Clearway Energy Group obtained NRG Community Solar's assets. Education Hawaii Department of Education operates public schools. Waialua Elementary School and Waialua High & Intermediate School are in the CDP. The Roman Catholic Diocese of Honolulu operates St. Michael School, a K-8 school. Hawaii State Public Library System operates the Waialua Library. History Many of the current families living in Waialua are the results of agricultural industry which began in the early 20th century. There was an increased demand for workers as the industry grew, resulting in workers being brought in from China, Portugal, Japan, Korea, Puerto Rico, Philippines, Spain and other areas. Upon arriving in Hawaii, many of these workers were assigned to work in the sugarcane plantations in Waialua. During the late 1980s and into the 1990s, the sugar production decreased as increasing labor and production costs caused producers to move overseas. Many of the families brought to Waialua during the sugar rush remained here and many of their descendants reside there today. During World War II the twin guns from USS Saratoga were installed off Kamehameha Highway near