Year	Percent
1973-01-01	18.054800000000000
1974-01-01	17.632100000000000
1975-01-01	18.885400000000000
1976-01-01	21.287900000000000
1977-01-01	25.476999999999997
1978-01-01	29.929900000000000
1979-01-01	25.383800000000000
1980-01-01	26.461800000000000
1981-01-01	26.262800000000000
1982-01-01	27.788800000000000
1983-01-01	28.202800000000000
1984-01-01	28.932300000000000
1985-01-01	29.290800000000000
1986-01-01	26.285200000000000
1987-01-01	26.716100000000000
1988-01-01	27.452100000000000
1989-01-01	27.518100000000000
1990-01-01	26.228500000000000
1991-01-01	26.607000000000000
1992-01-01	26.607000000000000
1993-01-01	26.607000000000000
1994-01-01	26.607000000000000
1995-01-01	26.607000000000000
1996-01-01	26.607000000000000
1997-01-01	26.607000000000000
1998-01-01	26.607000000000000
1999-01-01	26.607000000000000
2000-01-01	26.607000000000000
2001-01-01	26.607000000000000
2002-01-01	26.607000000000000
2003-01-01	26.607000000000000
2004-01-01	26.607000000000000
2005-01-01	31.925300000000000
2006-01-01	22.639100000000000
2007-01-01	22.690600000000000
2008-01-01	25.637500000000000
2009-01-01	28.467600000000000
2010-01-01	25.439900000000000
2011-01-01	23.118100000000000
2012-01-01	23.827100000000000