Year	Percent
1991	51.241
1992	51.399
1993	50.954
1994	50.751
1995	50.988
1996	51.9
1997	52.616
1998	52.118
1999	52.39
2000	53.293
2001	52.975
2002	52.707
2003	52.638
2004	52.611
2005	50.262
2006	48.352
2007	46.935
2008	46.06
2009	44.248
2010	44.578
2011	45.722
2012	45.215
2013	47.262
2014	40.371
2015	40.346
2016	41.218
2017	41.277
2018	41.775
2019	41.811
2020	41.66
2021	41.621
2022	41.661