| Year of joining | Answer | % Correct |
|---|---|---|
| 1949 | Canada | 100%
|
| 1949 | Denmark | 100%
|
| 1949 | France | 100%
|
| 1955 | Germany | 100%
|
| 1949 | Norway | 100%
|
| 1949 | Portugal | 100%
|
| 1949 | Belgium | 95%
|
| 2004 | Estonia | 95%
|
| 1949 | Iceland | 95%
|
| 1949 | Italy | 95%
|
| 2004 | Latvia | 95%
|
| 2004 | Lithuania | 95%
|
| 1949 | Netherlands | 95%
|
| 1982 | Spain | 95%
|
| 1949 | United Kingdom | 95%
|
| 1949 | Usa | 95%
|
| 1952 | Greece | 91%
|
| 1949 | Luxembourg | 91%
|
| 2009 | Albania | 86%
|
| 2004 | Bulgaria | 86%
|
| 2009 | Croatia | 86%
|
| 1999 | Czechia | 86%
|
| 1999 | Hungary | 86%
|
| 2020 | North Macedonia | 86%
|
| 1999 | Poland | 86%
|
| 2004 | Romania | 86%
|
| 2004 | Slovakia | 82%
|
| 2004 | Slovenia | 82%
|
| 1952 | Türkyie | 82%
|
| 2017 | Montenegro | 73%
|