| Span | Country | % Correct |
|---|---|---|
| 1975-Present | China | 97%
|
| 1922-1991 | Soviet Union | 97%
|
| 1976-Present | Vietnam | 92%
|
| 1976-Present | Cuba | 85%
|
| 1972-Present | North Korea | 85%
|
| 1963-1992 | Yugoslavia | 75%
|
| 1965-1989 | Romania | 69%
|
| 1976-1989 | Poland | 66%
|
| 1971-1991 | Bulgaria | 64%
|
| 1968-1990 | East Germany | 61%
|
| 1960-1990 | Czechoslovakia | 59%
|
| 1960-1990 | Mongolia | 56%
|
| 1972-1989 | Hungary | 54%
|
| 1976-1991 | Albania | 53%
|
| 1969-1991 | Somalia | 25%
|