| Year joined | Answer | % Correct |
|---|---|---|
| 1981 | Greece | 100%
|
| 1952 | Italy | 100%
|
| 1952 | France | 98%
|
| 1952 | Germany | 98%
|
| 2004 | Poland | 98%
|
| 1986 | Portugal | 98%
|
| 1986 | Spain | 98%
|
| 1952 | Belgium | 95%
|
| 1973 | Denmark | 95%
|
| 1995 | Finland | 95%
|
| 2007 | Romania | 95%
|
| 1952 | Netherlands | 93%
|
| 1995 | Sweden | 93%
|
| 2004 | Czech Republic | 90%
|
| 1995 | Austria | 88%
|
| 1973 | Ireland | 88%
|
| 2004 | Hungary | 86%
|
| 1952 | Luxembourg | 86%
|
| 2004 | Slovakia | 86%
|
| 2013 | Croatia | 83%
|
| 2004 | Latvia | 83%
|
| 2004 | Slovenia | 83%
|
| 2007 | Bulgaria | 81%
|
| 2004 | Estonia | 81%
|
| 2004 | Lithuania | 81%
|
| 2004 | Malta | 79%
|
| 1973 | United Kingdom | 74%
|
| 2004 | Cyprus | 64%
|