1993 184 vehicles 1992 288 vehicles 1991 479 vehicles 1990 976 vehicles 1989 2,440 vehicles 1988 11,798 vehicles 1987 10,184 vehicles 1986 9,806 vehicles 1985 9,306 vehicles 1984 7,068 vehicles 1983 6,134 vehicles 1982 4,423 vehicles 1981 4,458 vehicles 1980 4,352 vehicles