Year	Percent
1990	49.529
1991	50.592
1992	51.322
1993	52.071
1994	53.396
1995	55.038
1996	55.601
1997	56.158
1998	56.12
1999	56.063
2000	57.611
2001	59.127
2002	60.604
2003	60.929
2004	61.624
2005	62.349
2006	61.24
2007	62.828
2008	63.582
2009	64.083
2010	63.924
2011	61.563
2012	63.971
2013	66.003
2014	66.622
2015	68.016
2016	69.381
2017	69.547
2018	69.713
2019	69.879
2020	70.045
2021	70.208
2022	70.371
2023	70.535
2024	70.702
2025	70.873
2026	71.047
2027	71.225
2028	71.405
2029	71.585
2030	71.763