Year	Percent
1991-01-01	41.6949996948242
1992-01-01	43.3450012207031
1993-01-01	42.4659996032715
1994-01-01	39.6940002441406
1995-01-01	32.3940010070801
1996-01-01	30.6140003204346
1997-01-01	30.7250003814697
1998-01-01	30.6310005187988
1999-01-01	30.6280002593994
2000-01-01	31.3980007171631
2001-01-01	33.6559982299805
2002-01-01	35.4319992065430
2003-01-01	33.6739997863770
2004-01-01	33.8129997253418
2005-01-01	33.6310005187988
2006-01-01	30.7040004730225
2007-01-01	29.3010005950928
2008-01-01	28.6450004577637
2009-01-01	28.8290004730225
2010-01-01	29.6550006866455
2011-01-01	31.5760002136230
2012-01-01	30.8689994812012
2013-01-01	32.5369987487793
2014-01-01	31.4820003509521
2015-01-01	33.2939987182617
2016-01-01	38.5000000000000
2017-01-01	39.7639999389648