| Accession | Country | % Correct |
|---|---|---|
| 1960 | United States | 100%
|
| 1960 | France | 96%
|
| 1960 | Norway | 96%
|
| 1960 | United Kingdom | 96%
|
| 1961 | Australia | 92%
|
| 1961 | Chile | 92%
|
| 1984 | Finland | 92%
|
| 1979 | Germany | 92%
|
| 1960 | New Zealand | 92%
|
| 1960 | Russia | 92%
|
| 1984 | Sweden | 92%
|
| 1983 | China | 88%
|
| 1965 | Denmark | 88%
|
| 1982 | Spain | 88%
|
| 1961 | Argentina | 83%
|
| 1960 | Belgium | 83%
|
| 1975 | Brazil | 83%
|
| 2010 | Portugal | 83%
|
| 1960 | South Africa | 83%
|
| 1988 | Canada | 79%
|
| 1960 | Japan | 79%
|
| 1967 | Netherlands | 79%
|
| 1961 | Poland | 79%
|
| 1986 | South Korea | 79%
|
| 1987 | Austria | 75%
|
| 1983 | India | 75%
|
| 1981 | Italy | 75%
|
| 1971 | Romania | 75%
|
| 1990 | Switzerland | 75%
|
| 1993 | Czech Republic | 71%
|
| 1984 | Hungary | 71%
|
| 2015 | Iceland | 71%
|
| 1981 | Peru | 71%
|
| 1992 | Ukraine | 71%
|
| 1978 | Bulgaria | 67%
|
| 1989 | Colombia | 67%
|
| 1987 | Greece | 67%
|
| 1993 | Slovakia | 67%
|
| 1996 | Turkey | 67%
|
| 1980 | Uruguay | 67%
|
| 1999 | Venezuela | 67%
|
| 1987 | Ecuador | 63%
|
| 2001 | Estonia | 63%
|
| 1987 | North Korea | 63%
|
| 2012 | Pakistan | 58%
|
| 2019 | Slovenia | 58%
|
| 2011 | Malaysia | 54%
|
| 2006 | Belarus | 50%
|
| 1984 | Cuba | 50%
|
| 2015 | Kazakhstan | 50%
|
| 1991 | Guatemala | 46%
|
| 2008 | Monaco | 42%
|
| 2015 | Mongolia | 38%
|
| 1981 | Papua New Guinea | 25%
|