Year Percent 1985-01-01 1.9978900000000002 1986-01-01 1.7369800000000000 1987-01-01 1.7831599999999999 1988-01-01 2.3981800000000000 1989-01-01 3.0168900000000000 1990-01-01 4.0351400000000000 1991-01-01 4.3923100000000000 1992-01-01 4.2468500000000000