Year	Percent
1990	52.801
1991	52.662
1992	52.309
1993	51.997
1994	51.797
1995	51.706
1996	51.781
1997	52.384
1998	52.563
1999	52.71
2000	52.965
2001	52.972
2002	53.026
2003	52.769
2004	52.863
2005	52.97
2006	53.088
2007	53.229
2008	53.349
2009	53.45
2010	53.562
2011	53.668
2012	53.77
2013	53.878
2014	53.919
2015	53.954
2016	53.961
2017	53.938
2018	53.916
2019	53.907
2020	53.917
2021	53.939
2022	53.979
2023	54.037
2024	54.108
2025	54.191
2026	54.279
2027	54.381
2028	54.491
2029	54.602
2030	54.713