1999 902 vehicles 1998 1,026 vehicles 1997 1,542 vehicles 1996 1,639 vehicles 1995 1,534 vehicles 1994 1,106 vehicles 1993 915 vehicles 1992 1,208 vehicles 1991 2,183 vehicles 1990 3,738 vehicles 1989 5,250 vehicles 1988 5,730 vehicles 1987 4,578 vehicles 1986 4,051 vehicles