Year	Percent
1991-01-01	49.2719993591309
1992-01-01	48.9860000610352
1993-01-01	45.9760017395020
1994-01-01	45.0069999694824
1995-01-01	44.4090003967285
1996-01-01	43.2779998779297
1997-01-01	42.9840011596680
1998-01-01	43.5909996032715
1999-01-01	45.3680000305176
2000-01-01	45.7770004272461
2001-01-01	45.9840011596680
2002-01-01	46.0330009460449
2003-01-01	46.7430000305176
2004-01-01	46.4830017089844
2005-01-01	46.5410003662109
2006-01-01	46.7719993591309
2007-01-01	46.6259994506836
2008-01-01	46.0960006713867
2009-01-01	44.9679985046387
2010-01-01	44.8600006103516
2011-01-01	45.1549987792969
2012-01-01	45.9010009765625
2013-01-01	46.7560005187988
2014-01-01	49.4920005798340
2015-01-01	51.0810012817383
2016-01-01	52.9029998779297
2017-01-01	53.2519989013672