Year	Percent
1999-12-31	3.4454
2000-12-31	4.3976
2001-12-31	4.2598
2002-12-31	3.3168
2003-12-31	2.3287
2004-12-31	2.1056
2005-12-31	2.1838
2006-12-31	3.0812
2007-12-31	4.2768
2008-12-31	4.6392
2009-12-31	1.2021
2010-12-31	0.7535
2011-12-31	1.3392
2012-12-31	0.4876
2013-12-31	0.1522
2014-12-31	0.1797
2015-12-31	0.0393
2016-12-31	0.2798
2017-12-31	0.3678
2018-12-31	0.36
2019-12-31	0.3911
2020-12-31	0.4356