Year	Percent
1961-01-01	2.0768299999999997
1962-01-01	2.1310200000000000
1963-01-01	3.2630800000000000
1964-01-01	4.5234000000000000
1965-01-01	5.2455500000000000
1966-01-01	5.5679300000000005
1967-01-01	6.0626200000000000
1968-01-01	6.4261300000000010
1969-01-01	6.7518400000000000
1970-01-01	3.9729699999999997
1971-01-01	4.1839000000000000
1972-01-01	4.7268000000000000
1973-01-01	6.0374500000000000
1974-01-01	6.4627500000000000
1975-01-01	6.2649800000000000
1976-01-01	7.2105800000000000
1977-01-01	7.6906899999999990
1978-01-01	7.9450199999999995
1979-01-01	8.5799500000000000
1980-01-01	9.0333200000000000
1981-01-01	9.7715600000000010
1982-01-01	10.3049000000000000
1983-01-01	10.5732000000000000
1984-01-01	13.0466000000000000
1985-01-01	14.0052000000000000
1986-01-01	14.4683000000000000
1987-01-01	14.6665000000000000
1988-01-01	15.5687000000000000
1989-01-01	16.7452000000000000
1990-01-01	16.9034000000000000
1991-01-01	18.8096000000000000
1992-01-01	17.5408000000000000
1993-01-01	15.1185000000000000
1994-01-01	17.4488000000000000
1995-01-01	17.0465000000000000
1996-01-01	16.3297000000000000
1997-01-01	20.3516000000000000
1998-01-01	25.7656000000000000
1999-01-01	27.5814000000000000
2000-01-01	27.6097000000000000
2001-01-01	29.0077000000000000
2002-01-01	32.6892000000000000
2003-01-01	35.6720000000000000
2004-01-01	33.9996000000000000
2005-01-01	33.2075000000000000
2006-01-01	31.5361000000000000
2007-01-01	28.7559000000000000
2008-01-01	27.3936000000000000