Year	Percent
1991	2.43422
1992	2.33514
1993	2.238
1994	2.14286
1995	2.05277
1996	1.96662
1997	1.88253
1998	1.80137
1999	1.72229
2000	1.64541
2001	1.56894
2002	1.51851
2003	1.4675
2004	1.41037
2005	1.35329
2006	1.29453
2007	1.23929
2008	1.18335
2009	1.14045
2010	1.08391
2011	1.09087
2012	1.09034
2013	1.08487
2014	1.07843
2015	1.07496
2016	1.0394
2017	1.00495
2018	0.97363
2019	0.94091