Year	Percent
1966-01-01	7.4505000000000000
1967-01-01	7.0559000000000000
1968-01-01	6.7246800000000000
1969-01-01	6.7246800000000000
1970-01-01	6.7246800000000000
1971-01-01	6.7246800000000000
1972-01-01	6.7246800000000000
1973-01-01	6.7246800000000000
1974-01-01	6.7246800000000000
1975-01-01	6.0834699999999990
1976-01-01	4.8400700000000000
1977-01-01	4.9359000000000000
1978-01-01	4.6310500000000000
1979-01-01	4.5851300000000000
1980-01-01	4.7094000000000000
1981-01-01	4.6011200000000000
1982-01-01	4.8557600000000000
1983-01-01	5.8441800000000010
1984-01-01	6.4368900000000000
1985-01-01	6.6837899999999990
1986-01-01	6.2016900000000000
1987-01-01	7.2324000000000000
1988-01-01	8.2771900000000000
1989-01-01	9.0816100000000010
1990-01-01	7.6414200000000000
1991-01-01	7.2825600000000000
1992-01-01	6.4575300000000000
1993-01-01	7.0674399999999995
1994-01-01	6.6443000000000000
1995-01-01	6.1238400000000000
1996-01-01	6.3687500000000000
1997-01-01	6.2847900000000000
1998-01-01	6.0859800000000000
1999-01-01	6.1198800000000000
2000-01-01	5.8552700000000000