| Year | Country | % Correct |
|---|---|---|
| 1950 | United States | 99%
|
| 1967 | United Kingdom | 97%
|
| 1966 | Canada | 95%
|
| 1967 | Germany | 90%
|
| 1960 | Japan | 86%
|
| 1963 | Mexico | 83%
|
| 1967 | Netherlands | 70%
|
| 1958 | Cuba | 42%
|
| 1966 | Philippines | 18%
|
| 1961 | Belarus | 5%
|