Year	Percent
1991	3.57962
1992	3.4403
1993	3.39003
1994	3.50965
1995	2.88455
1996	2.69786
1997	2.8225
1998	2.45611
1999	2.18608
2000	1.88829
2001	2.02607
2002	1.96643
2003	2.00159
2004	2.11832
2005	2.07664
2006	1.44004
2007	1.12987
2008	1.48982
2009	1.48485
2010	1.38447
2011	1.32157
2012	1.31787
2013	1.28078
2014	1.23996
2015	1.19399
2016	1.15785
2017	1.12722
2018	1.09069
2019	1.08431