1997 155 vehicles 1996 1,518 vehicles 1995 3,649 vehicles 1994 4,970 vehicles 1993 5,306 vehicles 1992 3,994 vehicles 1991 1,424 vehicles 1990 1,631 vehicles 1989 2,934 vehicles 1988 2,310 vehicles 1987 2,428 vehicles 1986 335 vehicles