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

Context paragraphs:
William Porcher Miles: William Porcher Miles (July 4, 1822 – May 11, 1899) was among the ardent States' Rights advocates, supporters of slavery, and Southern secessionists who came to be known as the "Fire-Eaters."  He is notable for having designed the most popular variant of the Confederate flag, originally rejected as the national flag in 1861, but adopted as a battle flag by the Army of Northern Virginia under General Robert E. Lee before being reincorporated by William Tappan Thompson into the second design of the national flag in 1862.

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.

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.

Flag of Laos: The flag of Laos consists of three horizontal stripes, with the middle stripe in blue being twice the height of the top and bottom red stripes.  In the middle is a white disc, the diameter of the disc is ⁄ the height of the blue stripe.  The flag ratio is 2:3.  The national flag of Laos was first adopted in 1945 under the short-lived Lao Issara government of 1945–46, then by the Pathet Lao.  It is one of the only few flags of a currently communist country (besides Cuba) that does not use any communist symbolism on a national flag and the only current communist country that does not use a five-pointed star in its flag as an emblem.  The current flag was adopted on December 2, 1975 when it became a socialist state.

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.

Day of the National Flag (Ukraine): 23 August is celebrated as the Day of the National Flag (Ukrainian: День Державного Прапора України "Day of the National Flag of Ukraine") in Ukraine; beginning with 2004.  July 24 was previously marked as National Flag Day in Kiev.  The first ceremonial raising of the yellow-and-blue Ukrainian flag in modern times took place on 24 July 1990 at the flagstaff of the Kiev City Council, two years before the flag was officially adopted as the National flag of the Ukrainian state (1992).

Flag of India: The National Flag of India is a horizontal rectangular tricolour of India saffron, white and India green; with the "Ashoka Chakra ", a 24-spoke wheel, in navy blue at its centre.  It was adopted in its present form during a meeting of the Constituent Assembly held on 22 July 1947, and it became the official flag of the Dominion of India on 15 August 1947.  The flag was subsequently retained as that of the Republic of India.  In India, the term "tricolour" (Hindi: तिरंगा , "Tiraṅgā " ) almost always refers to the Indian national flag.  The flag is based on the "Swaraj " flag, a flag of the Indian National Congress designed by Pingali Venkayya.

List of Estonian flags: The national flag of Estonia is a tricolour featuring three equal horizontal bands of blue (top), black, and white.  The normal size is 105 × 165 cm.  In Estonian it is colloquially called the ""sinimustvalge"" (literally "blue-black-white"), after the colours of the bands.  The flag became associated with Estonian nationalism and was used as the national flag ("riigilipp") when the Estonian Declaration of Independence was issued on February 24, 1918.  The flag was formally adopted on November 21, 1918.  On December 12, 1918 was the first time the flag was raised as the national symbol atop of the Pikk Hermann Tower in Tallinn.

Flag code of India: The Flag Code of India is a set of laws, practices and conventions that apply to the display of the national flag.Flag Code of India, 2002, has been divided into three parts.  Part I of the code contains a general description of the national flag.  Part II of the code is devoted to the display of the national flag by members of public, private organizations, educational institutions, etc.  Part III of the code relates to display of the national flag by Central and state governments and their organizations and agencies.

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.

Supporting paragraphs: Flag of Ghana Theodosia Okoh
Answer: 1957