MONTANA P = Truck/Tractor S = Service Truck T = Trailer   1977 1978 1979   1979 1980 1980   1981 1981 1982   1983 1983 1984   1984 1985 1985   1986 1986 1987   1987 1988 1988   1989 1989 1990   1990 1991 1991   1991 1992 1992   1992 1993 1993   1993 1994 1994   1994 1995 1995   1995 1996 1996   1997 1997 1997   1998 1998 1998   1999 1999 1999   2000 2001 2001   2002 2002 2002   2003 2003 2004   2004 2005 2006   2007 2008