Year	Percent
1961-01-01	0.8483980000000000
1962-01-01	0.7734810000000001
1963-01-01	2.7662800000000000
1964-01-01	4.8650500000000000
1965-01-01	6.7894399999999990
1966-01-01	7.8533500000000000
1967-01-01	8.6577300000000000
1968-01-01	8.7716000000000000
1969-01-01	9.3107300000000000
1970-01-01	5.9086800000000000
1971-01-01	6.4582500000000000
1972-01-01	6.7064000000000000
1973-01-01	7.3143899999999995
1974-01-01	7.5240000000000000
1975-01-01	8.0716100000000000
1976-01-01	8.2095899999999990
1977-01-01	7.7057300000000000
1978-01-01	9.1368800000000000
1979-01-01	9.6158399999999990
1980-01-01	9.2492800000000000
1981-01-01	9.7759400000000000
1982-01-01	9.7546800000000000
1983-01-01	8.7085300000000000
1984-01-01	9.4822500000000000
1985-01-01	9.8124000000000000
1986-01-01	9.6358699999999990
1987-01-01	10.2926000000000000
1988-01-01	11.4679000000000000
1989-01-01	11.6302000000000000
1990-01-01	11.8128000000000000
1991-01-01	13.5906000000000000
1992-01-01	11.7171000000000000
1993-01-01	7.3648300000000000
1994-01-01	6.7652300000000000
1995-01-01	7.9396300000000000
1996-01-01	10.8602000000000000
1997-01-01	15.1829000000000000
1998-01-01	19.1230000000000000
1999-01-01	22.6281000000000000
2000-01-01	23.4251000000000000
2001-01-01	21.9679000000000000
2002-01-01	21.0673000000000000
2003-01-01	20.3471000000000000
2004-01-01	18.2949000000000000
2005-01-01	19.5394000000000000
2006-01-01	21.1852000000000000
2007-01-01	18.5169000000000000
2008-01-01	17.0585000000000000