Year	Percent
1980-01-01	1.9981900000000001
1981-01-01	2.4792900000000000
1982-01-01	3.7139900000000003
1983-01-01	4.6970500000000000
1984-01-01	5.9682000000000000
1985-01-01	7.0597600000000010
1986-01-01	6.2974200000000000
1987-01-01	6.6717500000000000
1988-01-01	7.0779200000000000
1989-01-01	7.8123700000000000
1990-01-01	7.8453000000000000
1991-01-01	9.2536399999999990
1992-01-01	8.9505000000000000
1993-01-01	10.1001000000000000
1994-01-01	10.9177000000000000
1995-01-01	10.2624000000000000
1996-01-01	10.6195000000000000
1997-01-01	11.5509000000000000
1998-01-01	13.8655000000000000
1999-01-01	16.3579000000000000
2000-01-01	21.5037000000000000
2001-01-01	27.1213000000000000
2002-01-01	32.5080000000000000
2003-01-01	37.5152000000000000
2004-01-01	41.1183000000000000
2005-01-01	41.0995000000000000
2006-01-01	51.0858000000000000
2007-01-01	54.8416000000000000
2008-01-01	52.3708000000000000
2009-01-01	64.5541000000000000
2010-01-01	66.3462000000000000
2011-01-01	62.8034000000000000
2012-01-01	68.8183000000000000
2013-01-01	67.2985000000000000
2014-01-01	59.2518000000000000
2015-01-01	61.5561000000000000
2016-01-01	60.7699000000000000