Year	Percent
1991	34.875
1992	22.134
1993	28.954
1994	26.183
1995	36.295
1996	42.467
1997	44.775
1998	43.714
1999	42.274
2000	43.414
2001	43.465
2002	41.764
2003	43.053
2004	49.458
2005	51.201
2006	51.384
2007	51.886
2008	53.278
2009	52.486
2010	52.934
2011	56.906
2012	56.864
2013	57.316
2014	54.672
2015	53.075
2016	51.879
2017	51.085
2018	50.934
2019	50.945
2020	50.959
2021	50.973
2022	50.987