Year	Percent
1990	45.875
1991	45.825
1992	45.994
1993	46.476
1994	47.349
1995	47.324
1996	47.119
1997	47.329
1998	48.04
1999	48.951
2000	49.262
2001	49.432
2002	49.935
2003	50.112
2004	49.779
2005	50
2006	50.233
2007	50.209
2008	50.007
2009	49.963
2010	50.165
2011	49.024
2012	49.09
2013	49.12
2014	49.43
2015	49.638
2016	49.732
2017	49.476
2018	49.205
2019	48.939
2020	48.677
2021	48.417
2022	48.17
2023	47.932
2024	47.694
2025	47.447
2026	47.205
2027	46.972
2028	46.742
2029	46.515
2030	46.295