Year	Percent
1975-01-01	20.5944
1976-01-01	17.8931
1977-01-01	16.2331
1978-01-01	14.5724
1979-01-01	14.7152
1980-01-01	13.3089
1981-01-01	12.2166
1982-01-01	13.0813
1983-01-01	27.0691
1984-01-01	20.9559
1985-01-01	36.4166
1986-01-01	30.6030
1987-01-01	27.4138
1988-01-01	15.5752
1989-01-01	13.9807
1990-01-01	21.0967
1991-01-01	14.1939
1992-01-01	15.5651
1993-01-01	15.1369
1994-01-01	15.1369
1995-01-01	15.1369
1996-01-01	15.1369
1997-01-01	15.1369
1998-01-01	15.1369
1999-01-01	15.1369
2000-01-01	15.1369
2001-01-01	28.9845
2002-01-01	36.1565
2003-01-01	29.7271
2004-01-01	30.1125
2005-01-01	26.1815
2006-01-01	26.7733
2007-01-01	33.6493
2008-01-01	26.8552
2009-01-01	22.6695
2010-01-01	20.9046
2011-01-01	18.6091
2012-01-01	24.9008
2013-01-01	26.8464
2014-01-01	28.9846
2015-01-01	31.7584
2016-01-01	19.9725
2017-01-01	34.2412