Year	Percent
1990	1.05435
1991	1.03494
1992	1.01101
1993	0.94182
1994	0.89347
1995	0.80975
1996	0.76415
1997	0.74938
1998	0.74785
1999	0.74558
2000	0.72005
2001	0.71608
2002	0.70511
2003	0.70643
2004	0.67564
2005	0.70424
2006	0.57794
2007	0.5075
2008	0.50113
2009	0.55624
2010	0.53983
2011	0.51004
2012	0.51604
2013	0.48138
2014	0.46413
2015	0.45323
2016	0.4427
2017	0.43365
2018	0.43135
2019	0.42945
2020	0.44177