Year	Percent
1990	2.85536
1991	2.78849
1992	3.23127
1993	2.32074
1994	1.49238
1995	6.43064
1996	6.22935
1997	7.12311
1998	6.81019
1999	6.54012
2000	6.39613
2001	3.58911
2002	3.25079
2003	3.17719
2004	3.10949
2005	3.03176
2006	2.97462
2007	2.9218
2008	2.8761
2009	2.84481
2010	2.8176
2011	2.79764
2012	2.78636
2013	2.68958
2014	2.59629
2015	2.5103
2016	2.42933
2017	2.34875
2018	2.28116
2019	2.21154
2020	2.19768