Year	Percent
1980-01-01	3.6917000000000000
1981-01-01	4.2382400000000000
1982-01-01	4.8060000000000000
1983-01-01	5.6220400000000000
1984-01-01	5.4599400000000005
1985-01-01	6.2161000000000000
1986-01-01	5.7349900000000000
1987-01-01	6.1497199999999990
1988-01-01	4.8371100000000000
1989-01-01	4.1871500000000000
1990-01-01	4.3038700000000000
1991-01-01	7.6408000000000000
1992-01-01	18.5251000000000000
1993-01-01	29.7182000000000000
1994-01-01	35.6309000000000000
1995-01-01	28.6732000000000000
1996-01-01	28.3829000000000000
1997-01-01	22.7385000000000000
1998-01-01	21.1369999999999970
1999-01-01	18.7608000000000000
2000-01-01	15.3113000000000000
2001-01-01	15.9570000000000000
2002-01-01	15.6833000000000000
2003-01-01	20.5073000000000000
2004-01-01	17.8621000000000000
2005-01-01	14.7133000000000000
2006-01-01	10.7519000000000000
2007-01-01	5.6683000000000000
2008-01-01	2.1040600000000000
2009-01-01	1.6128600000000000
2010-01-01	3.5283700000000000
2011-01-01	6.5614600000000000
2012-01-01	7.9850200000000000
2013-01-01	8.8965500000000000
2014-01-01	9.4550300000000000
2015-01-01	10.2651000000000000
2016-01-01	9.0665500000000000