Year	Percent
1990	64.554
1991	64.482
1992	64.379
1993	64.346
1994	64.361
1995	64.405
1996	64.302
1997	64.279
1998	64.262
1999	64.252
2000	64.212
2001	64.186
2002	64.162
2003	64.078
2004	64.092
2005	64.082
2006	64.114
2007	64.143
2008	64.147
2009	64.139
2010	64.133
2011	64.139
2012	64.109
2013	63.65
2014	63.52
2015	63.393
2016	63.381
2017	63.34
2018	63.305
2019	63.278
2020	63.262
2021	63.302
2022	63.36
2023	63.434
2024	63.517
2025	63.607
2026	63.7
2027	63.796
2028	63.894
2029	63.995
2030	64.099