Year	Percent
1990	34.227
1991	34.225
1992	34.219
1993	34.223
1994	34.232
1995	34.303
1996	34.312
1997	34.349
1998	34.424
1999	34.516
2000	34.593
2001	34.683
2002	34.754
2003	34.882
2004	35.009
2005	35.137
2006	35.221
2007	37.336
2008	39.493
2009	41.682
2010	43.89
2011	46.118
2012	46.234
2013	46.342
2014	46.463
2015	46.618
2016	46.777
2017	47.167
2018	47.549
2019	47.918
2020	48.273
2021	48.62
2022	48.955
2023	49.282
2024	49.601
2025	49.915
2026	50.228
2027	50.539
2028	50.851
2029	51.173
2030	51.509