Year	Percent
1986-01-01	24.3614596471515
1987-01-01	24.8707566112393
1988-01-01	26.0622423639281
1989-01-01	27.2838534212127
1990-01-01	27.8894679777921
1991-01-01	27.5872953644401
1992-01-01	29.0349526879596
1993-01-01	31.0217332931001
1994-01-01	30.7855991252780
1995-01-01	30.7245300056843
1996-01-01	31.2364039975608
1997-01-01	31.9362940719184
1998-01-01	32.4321046823212
1999-01-01	31.7929959194636
2000-01-01	31.8906014818708
2001-01-01	31.4216298699940
2002-01-01	31.4569099224249
2003-01-01	32.7802480809706
2004-01-01	33.8704191169553
2005-01-01	35.0967738463174
2006-01-01	34.8343214757204
2007-01-01	35.7428961252362
2008-01-01	36.9823942011632
2009-01-01	36.8752750194620
2010-01-01	40.9666189279738
2011-01-01	43.2449152267419
2012-01-01	43.8377063637172
2013-01-01	44.4319634284310
2014-01-01	45.0758500318303
2015-01-01	44.9336427937918
2016-01-01	44.6607361033399
2017-01-01	45.0342791502826