Year	Percent
1970-01-01	4.5128900000000005
1971-01-01	4.7410200000000000
1972-01-01	6.2597500000000000
1973-01-01	6.0062900000000000
1974-01-01	6.2256700000000000
1975-01-01	6.9758700000000000
1976-01-01	7.2951600000000010
1977-01-01	8.9107300000000010
1978-01-01	10.6825000000000000
1979-01-01	10.0408000000000000
1980-01-01	9.9636700000000000
1981-01-01	9.6237700000000000
1982-01-01	9.2343100000000000
1983-01-01	8.9386500000000000
1984-01-01	8.5272800000000010
1985-01-01	8.9864300000000000
1986-01-01	10.1805000000000000
1987-01-01	11.4674000000000000
1988-01-01	13.0462000000000000
1989-01-01	13.1242000000000000
1990-01-01	12.7838000000000000
1991-01-01	14.5045000000000000
1992-01-01	14.8932000000000000
1993-01-01	15.2199000000000000
1994-01-01	21.3025000000000000
1995-01-01	14.6463000000000000
1996-01-01	17.2165000000000000
1997-01-01	18.5175000000000000
1998-01-01	19.9418000000000000
1999-01-01	23.7715000000000000
2000-01-01	26.5293000000000000
2001-01-01	27.4186000000000000
2002-01-01	28.8957000000000000
2003-01-01	28.8942000000000000
2004-01-01	31.3139000000000000
2005-01-01	30.6544000000000000
2006-01-01	34.9538000000000000
2007-01-01	36.9513000000000000
2008-01-01	34.9677000000000000
2009-01-01	36.8357000000000000
2010-01-01	39.4900000000000000
2011-01-01	38.0440000000000040
2012-01-01	38.1074000000000000
2013-01-01	40.2158000000000000
2014-01-01	40.2787000000000000
2015-01-01	41.3026000000000000
2016-01-01	44.6788000000000000