Year	Percent
1990	56.95
1991	56.962
1992	56.86
1993	56.536
1994	56.464
1995	56.433
1996	56.502
1997	56.517
1998	56.502
1999	56.441
2000	56.373
2001	56.384
2002	56.277
2003	56.264
2004	56.29
2005	56.368
2006	56.539
2007	56.702
2008	56.789
2009	56.775
2010	56.76
2011	56.79
2012	56.802
2013	56.805
2014	56.775
2015	56.714
2016	56.629
2017	56.673
2018	56.717
2019	56.76
2020	56.804
2021	56.847
2022	56.891
2023	56.934
2024	56.978
2025	57.021
2026	57.065
2027	57.108
2028	57.152
2029	57.196
2030	57.239