| Joined | Left | Country | % Correct |
|---|---|---|---|
| 1936 | 1991 | Armenia | 95%
|
| 1936 | 1991 | Georgia | 95%
|
| 1936 | 1991 | Kazakhstan | 94%
|
| 1940 | 1990 | Latvia | 94%
|
| 1922 | 1991 | Russia | 94%
|
| 1922 | 1991 | Ukraine | 94%
|
| 1936 | 1991 | Azerbaijan | 92%
|
| 1924 | 1991 | Uzbekistan | 92%
|
| 1922 | 1991 | Belarus | 91%
|
| 1940 | 1990 | Estonia | 91%
|
| 1940 | 1990 | Lithuania | 91%
|
| 1924 | 1991 | Turkmenistan | 91%
|
| 1929 | 1991 | Tajikistan | 89%
|
| 1936 | 1991 | Kyrgyzstan | 88%
|
| 1940 | 1991 | Moldova | 83%
|