Year	Percent
1991	5.22826
1992	5.21839
1993	5.20421
1994	5.19322
1995	5.18098
1996	5.1719
1997	5.15728
1998	3.02753
1999	2.8666
2000	2.86415
2001	2.86049
2002	2.8596
2003	2.85584
2004	2.855
2005	2.85137
2006	2.84907
2007	2.84824
2008	3.17184
2009	3.18857
2010	3.20387
2011	3.30944
2012	3.32572
2013	3.31107
2014	3.29138
2015	3.26363
2016	3.22906
2017	3.23582