Year	Percent
1990	32.843
1991	33.09
1992	33.48
1993	33.783
1994	33.813
1995	33.666
1996	34.063
1997	34.394
1998	34.746
1999	35.415
2000	36.015
2001	35.442
2002	37.227
2003	36.567
2004	34.313
2005	36.183
2006	36.779
2007	39.275
2008	40.661
2009	41.359
2010	42.559
2011	44.689
2012	47.467
2013	50.115
2014	52.215
2015	53.834
2016	55.432
2017	55.731
2018	55.989
2019	56.243
2020	56.511
2021	56.769
2022	57.025
2023	57.268
2024	57.493
2025	57.693
2026	57.859
2027	58.003
2028	58.121
2029	58.21
2030	58.267