1993 161 vehicles 1992 116 vehicles 1991 115 vehicles 1990 132 vehicles 1989 231 vehicles 1988 278 vehicles 1987 266 vehicles 1986 296 vehicles 1985 384 vehicles 1984 719 vehicles 1983 821 vehicles 1982 614 vehicles 1981 462 vehicles 1980 1,004 vehicles