1991 257 vehicles 1990 1,870 vehicles 1989 2,676 vehicles 1988 2,563 vehicles 1987 2,167 vehicles 1986 2,022 vehicles 1985 2,108 vehicles 1984 1,183 vehicles 1983 1,265 vehicles 1982 1,620 vehicles 1981 1,143 vehicles 1980 1,388 vehicles