Year	Percent
1991	50.328
1992	52.78
1993	53.423
1994	50.525
1995	50.832
1996	50.567
1997	47.438
1998	50.82
1999	43.057
2000	42.285
2001	45.062
2002	44.963
2003	47.228
2004	47.73
2005	43.138
2006	45.539
2007	53.167
2008	54.244
2009	51.639
2010	52.468
2011	52.573
2012	52.707
2013	52.227
2014	50.451
2015	53.312
2016	57.148
2017	57.311
2018	57.405
2019	57.461
2020	57.46
2021	57.365
2022	57.262