was 65 years of age or older. The average household size was 2.73 and the average family size was 3.50. In the city, the population was spread out, with 25.9% under the age of 18, 7.0% from 20 to 24, 13.3% from 25 to 34, 13.0% from 45 to 54, 9.8% from 55 to 64 and 6.8% who were 65 years of age or older. The median age was 35.2 years. For every 100 females, there were 97.4 males. For every 100 females age 18 and over, there were 94.9 males. The median income for a household in the city was $30,869, and the median income for a family was $36,337. Males had a median income of $32,412 versus $26,349 for females. The per capita income for the city was $16,782. 30.2% of the population were below the poverty line. Economy Port of Fort Pierce According to the U.S. Army Corps of Engineers, an average of 350,000 tons of waterborne commerce moves through the Port of Fort Pierce annually. Major commodities which are dependent on the port include citrus exports, cement and aragonite imports. The last navigation improvements at Fort Pierce were authorized by the U.S. Congress in the Water Resources Development Act of 1988 dated November 17, 1988 and construction was completed in August 1996. The existing entrance channel is 400 feet wide and 30 feet deep, the interior channel is 250 feet wide and 28 feet deep, the existing turning basin is 1,100 feet square and 28 feet deep, and the north access channel is located immediately north of the main turning basin is 1,250 feet long, 250 feet wide and 28 feet deep. In late 2014 dredging efforts were completed in the port. The dredging effort included both beach placement of beach quality sand on the beach immediately south of the Inlet as well as placement of non beach quality sand in the approved offshore disposal area. Arts and culture Tourist attractions A.E. Backus Museum and Gallery Arcade Building Art Mundo at the Art Bank Boston House Dust Tracks of Zora Neale Hurston Harbor Branch Oceanographic Institute Heathcote Botanical Gardens Historic Main Street Florida Power and Light Energy Encounter Lincoln Park Main Street Old Fort Pierce City Hall Old Fort Park Manatee Center Navy UDT-SEAL Museum (Fort Pierce was the original home of the United States Navy SEALs) Smithsonian Marine Ecosystem Exhibit St. Lucie County Marine Center