Year	Percent
1973-01-01	13.27350
1974-01-01	14.61820
1975-01-01	17.75770
1976-01-01	20.72380
1977-01-01	21.73120
1978-01-01	17.13430
1979-01-01	13.23090
1980-01-01	11.79600
1981-01-01	14.19620
1982-01-01	14.12910
1983-01-01	12.16150
1984-01-01	12.32490
1985-01-01	10.29410
1986-01-01	8.79995
1987-01-01	8.20242
1988-01-01	6.53032
1989-01-01	6.76010
1990-01-01	8.56368
1991-01-01	10.77300
1992-01-01	13.65890
1993-01-01	14.53990
1994-01-01	14.44740
1995-01-01	13.16890
1996-01-01	10.54370
1997-01-01	9.76525
1998-01-01	11.31890
1999-01-01	13.44530
2000-01-01	15.13700
2001-01-01	16.53910
2002-01-01	18.62570
2003-01-01	20.90360
2004-01-01	22.01320
2005-01-01	20.21980
2006-01-01	19.70530
2007-01-01	20.88370
2008-01-01	25.30790
2009-01-01	30.51130
2010-01-01	27.42270
2011-01-01	26.20250
2012-01-01	30.55430
2013-01-01	32.31020
2014-01-01	31.79570
2015-01-01	34.90180
2016-01-01	32.53210