Year Percent 1980-01-01 8.43955000000000000 1981-01-01 7.38595000000000000 1982-01-01 5.28621000000000000 1983-01-01 3.23619000000000000 1984-01-01 2.23265999999999960 1985-01-01 1.97804000000000020 1986-01-01 3.12544000000000000 1987-01-01 3.65536000000000000 1988-01-01 3.96621000000000000 1989-01-01 4.02316999999999950 1990-01-01 3.47609000000000000 1991-01-01 4.39960000000000000 1992-01-01 6.02584000000000050 1993-01-01 7.92263000000000100 1994-01-01 7.50373000000000000 1995-01-01 6.02361000000000000 1996-01-01 3.90385000000000000 1997-01-01 1.80055000000000000 1998-01-01 0.46957700000000000 1999-01-01 0.43822100000000000 2000-01-01 0.40405300000000000 2001-01-01 0.38471500000000003 2002-01-01 0.23916800000000000