Year	Percent
1991	33.111
1992	23.139
1993	34.542
1994	49.959
1995	59.524
1996	63.256
1997	62.43
1998	56.09
1999	57.807
2000	62.723
2001	64.679
2002	64.023
2003	65.581
2004	65.382
2005	65.397
2006	70.695
2007	71.71
2008	65.268
2009	64.222
2010	61.308
2011	62.349
2012	62.722
2013	61.358
2014	60.745
2015	57.954
2016	56.31
2017	57.725
2018	57.719
2019	57.768
2020	57.898
2021	58.046
2022	57.936