Year	Percent
1968-01-01	0.076369000000000000
1969-01-01	0.069362000000000010
1970-01-01	0.064946000000000000
1971-01-01	0.060192999999999997
1972-01-01	0.056729999999999996
1973-01-01	0.049777999999999996
1974-01-01	0.094706000000000000
1975-01-01	0.115275000000000000
1976-01-01	0.112484999999999990
1977-01-01	0.099277000000000000
1978-01-01	0.093010000000000000
1979-01-01	0.083471000000000000
1980-01-01	0.083225000000000000
1981-01-01	0.161857000000000000
1982-01-01	0.168150000000000000
1983-01-01	0.152774000000000000
1984-01-01	0.182010999999999980
1985-01-01	0.379669000000000000
1986-01-01	0.553600000000000000
1987-01-01	0.921502000000000000
1988-01-01	1.003650000000000000
1989-01-01	1.159900000000000000
1990-01-01	1.301240000000000000
1991-01-01	2.037509999999999700
1992-01-01	1.734750000000000000
1993-01-01	2.065530000000000000
1994-01-01	1.908270000000000100
1995-01-01	1.777050000000000000
1996-01-01	1.831520000000000000
1997-01-01	2.097870000000000000
1998-01-01	2.180500000000000000
1999-01-01	1.787280000000000000
2000-01-01	1.636930000000000000
2001-01-01	1.450000000000000000
2002-01-01	1.264200000000000000
2003-01-01	1.095580000000000000
2004-01-01	1.608860000000000000
2005-01-01	2.059580000000000000
2006-01-01	2.846300000000000000
2007-01-01	3.353640000000000000
2008-01-01	3.594250000000000000
2009-01-01	3.386480000000000000
2010-01-01	2.768170000000000000
2011-01-01	2.781110000000000000
2012-01-01	3.034570000000000000
2013-01-01	3.860350000000000000
2014-01-01	4.213580000000000000
2015-01-01	4.160890000000000000
2016-01-01	3.706919999999999800