Year	Percent
1990	43.147
1991	43.384
1992	43.876
1993	44.455
1994	44.312
1995	44.753
1996	45.153
1997	45.752
1998	46.187
1999	46.15
2000	44.406
2001	42.731
2002	41.125
2003	39.558
2004	38.026
2005	36.531
2006	40.467
2007	41.261
2008	42.07
2009	42.899
2010	44.494
2011	42.49
2012	40.493
2013	43.676
2014	46.874
2015	50.293
2016	50.84
2017	50.885
2018	50.931
2019	50.982
2020	51.038
2021	51.105
2022	51.177
2023	51.253
2024	51.33
2025	51.408
2026	51.493
2027	51.58
2028	51.663
2029	51.733
2030	51.787