Simplify the following text for a Grade 6 native English-speaking person.
Original: `` Sons and Daughters of Saint Lucia '' is the national anthem of Saint Lucia , first adopted in 1967 upon achieving self government , and confirmed as the official anthem upon independence in 1979 .
Simplified: `` Sons and Daughters of Saint Lucia '' is the national anthem of Saint Lucia . The song has been used since the country became independent in 1979 .