Year	Percent
1991	56.129
1992	56.156
1993	56.074
1994	55.762
1995	55.179
1996	55.279
1997	55.06
1998	54.639
1999	54.175
2000	53.725
2001	53.154
2002	52.537
2003	51.857
2004	51.097
2005	50.283
2006	49.731
2007	49.124
2008	48.505
2009	47.918
2010	47.386
2011	47.215
2012	46.973
2013	46.688
2014	46.369
2015	46.005
2016	45.813
2017	45.533
2018	45.241
2019	44.939
2020	44.633
2021	44.325
2022	44.011