Year	Percent
1986-01-01	32.7540853656428
1987-01-01	31.8593328973838
1988-01-01	32.5903444049024
1989-01-01	30.5055793612888
1990-01-01	30.6555683213608
1991-01-01	31.2926115323539
1992-01-01	32.5640668598707
1993-01-01	34.8597370757112
1994-01-01	36.6043984049959
1995-01-01	38.9313227631879
1996-01-01	42.8643397809236
1997-01-01	44.3142763391795
1998-01-01	46.1455893599278
1999-01-01	48.1644554357305
2000-01-01	47.7732867615798
2001-01-01	51.7010961457432
2002-01-01	53.9271522379361
2003-01-01	57.6797274944744
2004-01-01	59.7013782035105
2005-01-01	62.3538751342618
2006-01-01	62.1537285393623
2007-01-01	64.1071035179305
2008-01-01	64.7272802235716
2009-01-01	66.3523347742454
2010-01-01	69.0979322093489
2011-01-01	69.5656372984918
2012-01-01	70.8822017664936
2013-01-01	72.2884054534982
2014-01-01	73.9738831091306
2015-01-01	72.7476280394652
2016-01-01	73.1754092341924
2017-01-01	74.5190788162619