Year	Percent
1975-01-01	2.1101400000000003
1976-01-01	2.0224300000000000
1977-01-01	2.0724800000000000
1978-01-01	2.3162500000000000
1979-01-01	2.0394200000000002
1980-01-01	1.5472500000000000
1981-01-01	1.5813400000000000
1982-01-01	1.7863700000000000
1983-01-01	2.9164000000000000
1984-01-01	3.7889100000000000
1985-01-01	7.6545200000000000
1986-01-01	12.8716000000000000
1987-01-01	23.5347000000000000
1988-01-01	28.0083000000000000
1989-01-01	24.1661000000000000
1990-01-01	26.8730000000000000
1991-01-01	32.8161000000000000
1992-01-01	21.2274000000000000
1993-01-01	22.8499000000000000
1994-01-01	26.0550000000000000
1995-01-01	24.4816000000000000
1996-01-01	14.1267000000000000
1997-01-01	25.1176000000000000
1998-01-01	54.5101000000000000
1999-01-01	61.7338000000000000
2000-01-01	75.5585000000000000
2001-01-01	78.9352000000000000
2002-01-01	53.9586000000000000
2003-01-01	41.1430000000000000
2004-01-01	40.7645000000000000
2005-01-01	43.0325000000000000
2006-01-01	53.9723000000000000
2007-01-01	77.9014000000000000
2008-01-01	102.5460000000000000
2009-01-01	84.1565000000000000
2010-01-01	46.7099000000000000
2011-01-01	41.8848000000000000
2012-01-01	38.2488000000000000
2013-01-01	34.6782000000000000
2014-01-01	33.1791000000000000
2015-01-01	37.1180000000000000
2016-01-01	36.7481000000000000
2017-01-01	36.5759000000000000