Year	Percent
1971-01-01	18.2768000000000000
1972-01-01	19.0186000000000000
1973-01-01	24.3744000000000000
1974-01-01	26.6172000000000000
1975-01-01	22.3596000000000000
1976-01-01	18.7754000000000000
1977-01-01	20.9885000000000000
1978-01-01	22.4522000000000000
1979-01-01	18.8730000000000000
1980-01-01	17.2980000000000000
1981-01-01	16.9427000000000000
1982-01-01	15.3796000000000000
1983-01-01	14.3562000000000000
1984-01-01	12.3147000000000000
1985-01-01	9.4441399999999990
1986-01-01	7.8177600000000010
1987-01-01	6.6732000000000000
1988-01-01	6.3333800000000000
1989-01-01	6.7331300000000000
1990-01-01	6.9936399999999990
1991-01-01	7.2967699999999995
1992-01-01	7.4072600000000010
1993-01-01	7.2528100000000000
1994-01-01	8.4638300000000000
1995-01-01	10.4110000000000000
1996-01-01	11.7538000000000000
1997-01-01	12.3698000000000000
1998-01-01	13.2277000000000000
1999-01-01	14.3790000000000010
2000-01-01	15.1776000000000000
2001-01-01	17.3361000000000000
2002-01-01	18.9275000000000000
2003-01-01	23.1614000000000000
2004-01-01	23.4667000000000000
2005-01-01	24.2308000000000000
2006-01-01	22.7201000000000000
2007-01-01	20.9435000000000000
2008-01-01	23.0005000000000000
2009-01-01	22.1792000000000000
2010-01-01	22.0856000000000000
2011-01-01	22.8845000000000000
2012-01-01	21.0169000000000000
2013-01-01	20.5004000000000000
2014-01-01	22.5617000000000000
2015-01-01	24.9510000000000000
2016-01-01	25.6012000000000000