Year	Percent
1961-01-01	4.2235000000000000
1962-01-01	4.1199699999999995
1963-01-01	3.9330100000000000
1964-01-01	3.5702100000000000
1965-01-01	3.2074900000000000
1966-01-01	3.3163699999999996
1967-01-01	3.6041500000000000
1968-01-01	3.7126800000000000
1969-01-01	3.5991300000000000
1970-01-01	1.9186200000000000
1971-01-01	1.8686000000000000
1972-01-01	1.9377300000000000
1973-01-01	1.8514900000000000
1974-01-01	1.4190399999999999
1975-01-01	2.0905600000000000
1976-01-01	3.9945300000000000
1977-01-01	4.9461800000000000
1978-01-01	5.7559200000000000
1979-01-01	6.7273700000000000
1980-01-01	7.3307899999999995
1981-01-01	7.2877500000000000
1982-01-01	7.3470800000000000
1983-01-01	8.0472200000000000
1984-01-01	10.3341000000000000
1985-01-01	9.9066800000000000
1986-01-01	9.1791000000000000
1987-01-01	9.3058600000000010
1988-01-01	10.1106000000000000
1989-01-01	11.3915000000000000
1990-01-01	12.1873000000000000
1991-01-01	15.9687000000000000
1992-01-01	17.7353000000000000
1993-01-01	18.3565000000000000
1994-01-01	20.7807000000000000
1995-01-01	17.3950000000000000
1996-01-01	14.2217000000000000
1997-01-01	14.1766000000000000
1998-01-01	16.2176000000000000
1999-01-01	17.2910000000000000
2000-01-01	19.0587000000000000
2001-01-01	19.3614000000000000
2002-01-01	20.1870000000000000
2003-01-01	21.5873000000000000
2004-01-01	22.0842000000000000
2005-01-01	24.2045000000000000
2006-01-01	21.5721000000000000
2007-01-01	17.4703000000000000
2008-01-01	16.8001000000000000