Year	Percent
1978-01-01	5.30239
1979-01-01	6.87600
1980-01-01	12.59780
1981-01-01	16.30370
1982-01-01	16.83310
1983-01-01	15.58500
1984-01-01	16.31680
1985-01-01	20.12830
1986-01-01	23.96230
1987-01-01	23.04000
1988-01-01	25.94210
1989-01-01	30.59030
1990-01-01	24.78890
1991-01-01	24.90470
1992-01-01	22.82110
1993-01-01	22.24090
1994-01-01	20.90060
1995-01-01	19.38500
1996-01-01	18.14330
1997-01-01	17.05330
1998-01-01	16.98820
1999-01-01	17.58270
2000-01-01	20.70400
2001-01-01	18.34700
2002-01-01	15.40850
2003-01-01	15.93910
2004-01-01	15.15060
2005-01-01	14.95710
2006-01-01	19.20420
2007-01-01	24.28480
2008-01-01	27.46140
2009-01-01	28.56310
2010-01-01	23.99380
2011-01-01	18.73490
2012-01-01	17.38640
2013-01-01	18.10530
2014-01-01	20.08140
2015-01-01	20.90030
2016-01-01	22.05330