Year	Percent
1980-01-01	8.22251
1981-01-01	8.99394
1982-01-01	10.19600
1983-01-01	10.48680
1984-01-01	11.82890
1985-01-01	13.89820
1986-01-01	15.68030
1987-01-01	15.96300
1988-01-01	17.73690
1989-01-01	20.10110
1990-01-01	24.87330
1991-01-01	27.66540
1992-01-01	28.95170
1993-01-01	30.20710
1994-01-01	30.94640
1995-01-01	32.47020
1996-01-01	36.01270
1997-01-01	38.03820
1998-01-01	40.67950
1999-01-01	42.30940
2000-01-01	41.11500
2001-01-01	39.80250
2002-01-01	39.47220
2003-01-01	37.50330
2004-01-01	35.43400
2005-01-01	32.61160
2006-01-01	31.70280
2007-01-01	31.22550
2008-01-01	29.55470
2009-01-01	29.83090
2010-01-01	29.94170
2011-01-01	30.35730
2012-01-01	31.86390
2013-01-01	32.81230
2014-01-01	32.81750
2015-01-01	33.71460
2016-01-01	34.39550