| Year | Letter | Country | % Correct |
|---|---|---|---|
| 1971 | Q | Qatar | 86%
|
| 1980 | Z | Zimbabwe | 86%
|
| 1990 | Y | Yemen | 85%
|
| 1650 | O | Oman | 83%
|
| 2011 | S | South Sudan | 82%
|
| 2008 | K | Kosovo | 78%
|
| 1980 | V | Vanuatu | 68%
|
| 1991 | A | Armenia | 67%
|
| 1991 | U | Uzbekistan | 67%
|
| 1991 | T | Turkmenistan | 63%
|
| 1992 | B | Bosnia & Herzegovina | 60%
|
| 1962 | J | Jamaica | 60%
|
| 2006 | M | Montenegro | 60%
|
| 1991 | R | Russia | 59%
|
| 2002 | E | East Timor | 57%
|
| 1990 | L | Latvia | 56%
|
| 1989 | H | Hungary | 55%
|
| 1948 | I | Israel | 55%
|
| 1991 | G | Georgia | 53%
|
| 1994 | P | Palau | 50%
|
| 1993 | C | Czech Republic | 49%
|
| 1978 | D | Dominica | 39%
|
| 1991 | F | FS of Micronesia | 33%
|
| 1990 | N | Namibia | 29%
|