| Continent | Date Adopted | Nation | % Correct |
|---|---|---|---|
| North America | 21 June 1788 | United States | 99%
|
| North America | 1 July 1867 | Canada | 89%
|
| North America | 5 February 1917 | Mexico | 88%
|
| Oceania | 1 January 1901 | Australia | 87%
|
| Europe | 8 May 1949 | Germany | 85%
|
| Asia | 3 May 1947 | Japan | 84%
|
| Europe | 7 February 1831 | Belgium | 82%
|
| Europe | 17 May 1814 | Norway | 80%
|
| Europe | 29 March 1815 | Netherlands | 79%
|
| Europe | 22 December 1947 | Italy | 78%
|
| Europe | 5 June 1849 | Denmark | 76%
|
| South America | 1 May 1853 | Argentina | 75%
|
| Asia | 26 January 1950 | India | 73%
|
| Europe | 1 October 1920 | Austria | 69%
|
| Europe | 29 December 1937 | Ireland | 66%
|
| Europe | 17 October 1868 | Luxembourg | 66%
|
| Asia | 17 July 1948 | South Korea | 63%
|
| Europe | 17 June 1944 | Iceland | 61%
|
| Asia | 18 August 1945 | Indonesia | 42%
|
| Europe | 5 October 1921 | Liechtenstein | 41%
|
| Oceania | 4 November 1875 | Tonga | 38%
|
| North America | 7 November 1949 | Costa Rica | 34%
|
| Asia | 11 January 1952 | Jordan | 24%
|
| Asia | 23 May 1926 | Lebanon | 21%
|
| Europe | 7 November 1922 | Latvia | 18%
|