Year	Percent
1990	50.765
1991	51.36
1992	52.389
1993	53.55
1994	55.138
1995	55.713
1996	55.477
1997	55.108
1998	55.208
1999	55.225
2000	55.138
2001	55.063
2002	55.264
2003	54.35
2004	53.552
2005	54.058
2006	54.415
2007	53.802
2008	53.191
2009	52.578
2010	52.157
2011	52.623
2012	51.558
2013	49.187
2014	50.321
2015	49.834
2016	48.356
2017	48.189
2018	47.976
2019	47.704
2020	47.363
2021	46.968
2022	46.521
2023	46.026
2024	45.493
2025	44.933
2026	44.372
2027	43.796
2028	43.23
2029	42.71
2030	42.253