Year Percent 1984-01-01 93.6930 1985-01-01 94.8097 1986-01-01 97.1938 1987-01-01 98.9543 1988-01-01 99.1317 1989-01-01 99.4065 1990-01-01 99.5968 1991-01-01 99.6902 1992-01-01 99.7620 1993-01-01 99.7111 1994-01-01 99.7347 1995-01-01 99.8331 1996-01-01 99.8213 1997-01-01 99.7860 1998-01-01 99.7176 1999-01-01 99.6071 2000-01-01 99.5350 2001-01-01 99.7547