| Joined | Country |
| founding member | |
| founding member | |
| joined September 1997 | |
| founding member | |
| founding member | |
| joined August 1995 | |
| founding member | |
| joined March 1990 | |
| | Joined | Country |
| founding member | |
| founding member | |
| founding member | |
| founding member | |
| joined august 1994 | |
| joined september 1997 - July 2004, rejoined 2008 | |
| founding member, currently suspended | |
|