1977 | Rigid (4.4MB) | Flexible |
1978 | Rigid (9.7MB) | Flexible |
1979 | Rigid (12.5MB) | Flexible |
1980 | Rigid | Flexible |
1981 | Rigid (8.2MB) | Flexible |
1982 | Rigid (17.4MB) | Flexible |
1983 | Rigid (9.6MB) | Flexible |
1984 | Rigid (10.6MB) | Flexible |
1985 | Rigid (11.1MB) | Flexible |
1986 | Rigid (10.4MB) | Flexible |
1987 | Rigid (10.6MB) | Flexible |
1988 | Rigid (12.5MB) | Flexible |
1989 | Rigid (14.1MB) | Flexible |
1990 | Rigid (15.6MB) | Flexible |
1991 | Rigid (14.8MB) | Flexible |
1992 | Rigid (15.8MB) | Flexible |
1993 | Rigid (14.7MB) | Flexible |
1994 | Rigid (13.9MB) | Flexible |
1995 | Rigid (12.7MB) | Flexible |
1996 | Rigid (32.3MB) | Flexible |
1997 | Rigid (18.6MB) | Flexible |
1998 | Rigid (7.9MB) | Flexible |
1999 | Rigid (17.8MB) | Flexible |