Year	Percent
1991	2.03165
1992	1.90224
1993	1.78371
1994	1.67592
1995	1.56376
1996	1.48333
1997	1.40907
1998	1.3214
1999	1.2658
2000	1.20815
2001	1.13013
2002	1.06888
2003	1.01724
2004	0.96692
2005	0.92022
2006	0.86583
2007	0.81342
2008	0.77757
2009	0.72667
2010	0.68721
2011	0.65285
2012	0.61744
2013	0.58245
2014	0.55008
2015	0.74253
2016	1.00691
2017	1.3586
2018	1.06665
2019	1.9808
