Year	Percent
1991	48.732
1992	51.486
1993	50.739
1994	50.583
1995	50.505
1996	50.019
1997	50.289
1998	49.668
1999	49.258
2000	48.913
2001	47.804
2002	47.337
2003	46.78
2004	46.787
2005	46.787
2006	46.754
2007	46.854
2008	46.867
2009	46.88
2010	46.861
2011	46.839
2012	46.832
2013	45.853
2014	43.185
2015	43.073
2016	43.135
2017	43.303
2018	43.476
2019	43.649
2020	43.819
2021	43.98
2022	44.199