Year	Percent
1990	47.747
1991	47.951
1992	48.105
1993	48.261
1994	48.469
1995	48.754
1996	48.927
1997	49.161
1998	49.378
1999	49.37
2000	49.467
2001	50.419
2002	51.407
2003	52.419
2004	53.427
2005	54.415
2006	55.42
2007	55.705
2008	55.985
2009	56.264
2010	53.546
2011	57.426
2012	61.107
2013	64.554
2014	64.814
2015	65.027
2016	65.246
2017	65.614
2018	65.96
2019	66.279
2020	66.57
2021	66.828
2022	67.063
2023	67.276
2024	67.462
2025	67.622
2026	67.753
2027	67.864
2028	67.969
2029	68.089
2030	68.234