Year	Percent
1990	10.79878
1991	10.57296
1992	10.34803
1993	9.30373
1994	9.14224
1995	10.15475
1996	9.40967
1997	9.84761
1998	9.72838
1999	9.66012
2000	9.55893
2001	9.68776
2002	9.59719
2003	9.50263
2004	9.5799
2005	9.49246
2006	9.377
2007	9.26445
2008	9.18355
2009	9.66951
2010	9.56451
2011	9.47078
2012	9.38465
2013	9.30114
2014	9.22049
2015	9.13064
2016	9.66904
2017	9.57058
2018	9.47621
2019	9.41789
2020	9.54756