Year Years 1980 6.337 1981 2.861 1982 2.779 1983 2.386 1984 0.8413 1985 0.9234 1986 0.4325 1987 -2.238 1988 -1.225 1989 -2.594 1990 -2.004 1991 0.068 1992 -0.6876 1993 -0.1523 1994 0.6728 1995 -0.3499 1996 -0.2702 1997 0.3519 1998 -0.9681 1999 -1.77 2000 -1.254 2001 -0.585 2002 0.08321 2003 0.6325 2004 0.191