Year	Percent
1991	67.637
1992	64.335
1993	61.044
1994	65.001
1995	71.205
1996	70.06
1997	73
1998	67.481
1999	70.364
2000	70.505
2001	64.906
2002	65.179
2003	60.821
2004	63.662
2005	64.24
2006	65.076
2007	66.442
2008	67.314
2009	62.095
2010	56.68
2011	56.495
2012	54.529
2013	52.274
2014	52.63
2015	54.529
2016	56.518
2017	57.205
2018	57.24
2019	56.799
2020	56.466
2021	56.041
2022	55.53