Year	Percent
1990	46.996
1991	47.129
1992	47.486
1993	47.871
1994	48.469
1995	49.053
1996	49.606
1997	50.201
1998	50.89
1999	51.673
2000	52.631
2001	53.675
2002	54.84
2003	56.062
2004	57.415
2005	58.735
2006	59.924
2007	61.169
2008	62.264
2009	63.202
2010	64.114
2011	64.868
2012	65.574
2013	66.25
2014	66.912
2015	67.544
2016	68.26
2017	68.662
2018	69.079
2019	69.49
2020	69.882
2021	70.262
2022	70.624
2023	70.963
2024	71.274
2025	71.554
2026	71.809
2027	72.036
2028	72.24
2029	72.425
2030	72.598