Year Years 1980 9.433 1981 9.241 1982 8.68 1983 8.941 1984 9.316 1985 8.99 1986 8.357 1987 8.113 1988 7.333 1989 6.573 1990 5.861 1991 4.451 1992 4.291 1993 2.298 1994 0.8094 1995 -0.3271 1996 -1.117 1997 -2.49 1998 -2.815 1999 -2.395 2000 -2.567 2001 -1.607 2002 -1.905 2003 -1.041