| Accession | Country | % Correct |
|---|---|---|
| 4th April 1949(Founders) | Belgium | 99%
|
| France | 92%
| |
| Canada | 90%
| |
| Denmark | 87%
| |
| Italy | 77%
| |
| Luxembourg | 76%
| |
| United Kingdom | 76%
| |
| Iceland | 75%
| |
| United States | 75%
| |
| 30th May 1982(Third Enlargement) | Spain | 70%
|
| Netherlands | 69%
| |
| Norway | 69%
| |
| 18th February 1952(First Enlargement) | Greece | 68%
|
| 12th March 1999(Fourth Enlargement) | Czech Republic | 66%
|
| Poland | 66%
| |
| Turkey | 66%
| |
| 9th May 1955(Second Enlargement) | (West) Germany | 66%
|
| 29th March 2004(Fifth Enlargement) | Bulgaria | 65%
|
| Croatia | 65%
| |
| Hungary | 65%
| |
| Portugal | 65%
| |
| 4th April 2009(Sixth Enlargement) | Albania | 63%
|
| Estonia | 63%
| |
| 27 March 2020(Eighth Enlargement) | North Macedonia | 63%
|
| Latvia | 62%
| |
| Lithuania | 62%
| |
| Slovakia | 62%
| |
| Slovenia | 62%
| |
| 5th June 2017(Seventh Enlargement) | Montenegro | 61%
|
| Romania | 59%
|