Question: The national flag of Ghana designed by Theodosia Okoh was adopted in which year?

full_context: Document 1: Theodosia Okoh: Theodosia Salome Okoh (13 June 1922 – 19 April 2015) was a Ghanaian stateswoman, teacher and artist known for designing Ghana's flag in 1957. She also played a leading role in the development of hockey in Ghana.
Document 2: Nicola Marschall: Nicola Marschall (1829 – February 24, 1917) was a German-American artist who supported the Confederate cause during the American Civil War. He designed the original Confederate flag, the Stars and Bars, as well as the official grey uniform of the Confederate army.
Document 3: Black Star of Africa: The Black Star of Africa is a black five-pointed star (★) symbolizing Africa in general and Ghana in particular. The Black Star Line, founded in 1919 by Marcus Garvey as part of the Back-to-Africa movement, modelled its name on that of the White Star Line, changing the colour from white to black to symbolise ownership by black people rather than white people. The black star became a symbol of Pan-Africanism and anti-colonialism. Described as the "Lodestar of African Freedom", the black star was used in 1957 by Theodosia Okoh in the design of the Flag of Ghana.
Document 4: Flag of Malaysia: The flag of Malaysia, also known as the (Malay: "Jalur Gemilang" (Stripes of Glory)), is composed of a field of 14 alternating red and white stripes along the fly and a blue canton bearing a crescent and a 14-point star known as the "Bintang Persekutuan" (Federal Star). The 14 stripes, of equal width, represent the equal status in the federation of the 13 member states and the federal government, while the 14 points of the star represent the unity between these entities. The crescent represents Islam, the country's official religion; the blue canton symbolises the unity of the Malaysian people; the yellow of the star and crescent is the royal colour of the Malay rulers.
Document 5: Flag of Singapore: The national flag of Singapore was adopted in 1959, the year Singapore became self-governing within the British Empire. It was reconfirmed as the national flag when the republic gained independence on 9 August 1965. Prior to its independence, it was the only state flag in Malaysia not to have a 1:2 ratio. The design is a horizontal bicolour of red above white, overlaid in the canton (upper-left quadrant) by a white crescent moon facing a pentagon of five small white five-pointed stars. The elements of the flag denote a young nation on the ascendant, universal brotherhood and equality, and national ideals.
Document 6: Mohamed Hamzah: Mohamed Hamzah (5 March 1918 – 19 February 1993) was the creator of the "Jalur Gemilang", the Flag of Malaysia. He was from Kampung Melayu Majidee, Johor Bahru, Johor.
Document 7: Ghana national football team: The Ghana national football team represents Ghana in international association football and has done so since the 1950s. The team is nicknamed the Black Stars after the Black Star of Africa in the Flag of Ghana. It is administered by the Ghana Football Association, the governing body for football in Ghana and the oldest football association in Africa (founded in 1920). Prior to 1957, the team played as the Gold Coast.
Document 8: Flag of Gabon: The flag of Gabon is a tricolour consisting of three horizontal green, yellow and blue bands. Adopted in 1960 to replace the previous colonial flag containing the French Tricolour at the canton, it has been the flag of the Gabonese Republic since the country gained independence that year. The design of the present flag entailed the removal the Tricolour and the widening of the yellow stripe at the centre.
Document 9: Gifty Mensah: Gifty Mensah (born 7 October 1998) is a Ghanaian badminton player. In 2011, she plays for Accra, compete at the Ghana Independence Day Open Championship. She won a gold in the women's doubles and a silver in the singles. At the same year, she was selected to represented her country to compete at the All-Africa Games. Teamed-up with Daniel Sam, they were the finalist at the 2015 Nigeria International tournament. In 2016, she was the runner-up at the Rose Hill International tournament in the mixed doubles event with Emmanuel Donkor, after battling with the Mauritanian Edoo and Louison. She also took the third place in the women's doubles event with Stella Amassah.
Document 10: Flag of Niue: The flag of Niue was adopted on 15 October 1975. It consists of the Union Jack in the upper left corner with a star in the middle of the Union Jack and four stars forming a diamond around it. It is very unusual for a flag based on a British ensign design, in having not only a yellow background, but also a defaced Union Jack in the canton.
Document 11: Flag of Saint Kitts and Nevis: The flag of Saint Kitts and Nevis consists of a yellow-edged black band containing two white stars that divides diagonally from the lower hoist-side corner, with a green upper triangle and red lower triangle. Adopted in 1983 to replace the flag of Saint Christopher-Nevis-Anguilla, it has been the flag of the Federation of Saint Kitts and Nevis since the country gained independence that year. Although the flag utilises the colours of the Pan-Africanist movement, the symbolism behind them is interpreted differently.
Document 12: Philip Gbeho: Philip Comi Gbeho (14 January 1904 – 24 September 1976) was a Ghanaian musician, composer and teacher. He was best known for his composition of the Ghana National Anthem. He was instrumental in the establishment of the Arts Council of Ghana and was a Director of Music and conductor of the National Symphony Orchestra in Ghana.
Document 13: Flag of Ghana: The national flag of Ghana was designed and adopted in 1957 and was flown until 1962, and then reinstated in 1966. It consists of the Pan-African colours of red, yellow, and green, in horizontal stripes, with a black five-pointed star in the centre of the gold stripe. The Ghanaian flag was the second African flag after the flag of the Ethiopian Empire to feature these colours. The flag's design influenced that of the flag of Guinea-Bissau (1973). It was designed by Theodosia Okoh.
Document 14: Emmanuel Ofosu Yeboah: Emmanuel Ofosu Yeboah is an athlete and activist from Koforidua, Ghana. Yeboah was born in 1977 with a severely deformed right leg. In 2001, he rode the 400 miles across Ghana to bring attention to the plight of the disabled in that country. In the process, he applied for a grant of a bicycle from the Challenged Athletes Foundation (CAF).
Document 15: God Bless Our Homeland Ghana: "God Bless Our Homeland Ghana" is the national anthem of Ghana. The anthem "God Bless Our Homeland Ghana" was originally written and composed by Philip Gbeho and adopted in 1957.
ground_truth: 1957