Year	Percent
1990	45.227
1991	47.972
1992	47.814
1993	47.335
1994	47.902
1995	47.858
1996	47.866
1997	48.322
1998	48.536
1999	49.076
2000	49.065
2001	49.363
2002	49.631
2003	49.986
2004	49.809
2005	50.7
2006	51.489
2007	52.014
2008	52.132
2009	52.531
2010	52.788
2011	53.657
2012	53.704
2013	54.31
2014	54.515
2015	54.608
2016	54.96
2017	55.027
2018	55.072
2019	55.1
2020	55.104
2021	55.042
2022	54.962
2023	54.854
2024	54.711
2025	54.528
2026	54.324
2027	54.094
2028	53.848
2029	53.604
2030	53.375