Year	Percent
1990	39.087
1991	39.691
1992	40.454
1993	41.27
1994	42.257
1995	43.464
1996	43.655
1997	43.812
1998	43.964
1999	44.145
2000	44.375
2001	44.312
2002	44.5
2003	44.954
2004	45.619
2005	46.279
2006	46.767
2007	47.269
2008	47.712
2009	47.886
2010	48.228
2011	48.737
2012	49.079
2013	49.126
2014	49.026
2015	48.854
2016	47.978
2017	47.401
2018	46.896
2019	46.44
2020	46.005
2021	45.244
2022	44.524
2023	43.873
2024	43.313
2025	42.84
2026	42.282
2027	41.791
2028	41.373
2029	41.033
2030	40.763