Year	Percent
1990	35.214
1991	35.826
1992	36.683
1993	37.645
1994	38.228
1995	39.585
1996	39.631
1997	41.832
1998	41.533
1999	40.745
2000	41.174
2001	40.553
2002	41.252
2003	40.78
2004	43.155
2005	43.855
2006	45.144
2007	45.698
2008	45.54
2009	46.15
2010	46.022
2011	46.446
2012	47.567
2013	47.612
2014	46.602
2015	46.931
2016	47.083
2017	47.334
2018	47.594
2019	47.855
2020	48.11
2021	48.363
2022	48.611
2023	48.852
2024	49.083
2025	49.301
2026	49.509
2027	49.705
2028	49.893
2029	50.08
2030	50.269