Year	Percent
1990	12.34
1991	14.73
1992	13.77
1993	13.09
1994	14.25
1995	13.057
1996	11.949
1997	10.924
1998	9.977
1999	9.103
2000	8.299
2001	7.56
2002	8.27
2003	7.66
2004	7.18
2005	7.387
2006	7.6
2007	8.32
2008	9.41
2009	9.33
2010	9.216
2011	8.682
2012	9.009
2013	9.142
2014	9.016
2015	8.935
2016	8.946
2017	9.023
2018	9.1
2019	9.177
2020	9.254
2021	9.331
2022	9.408
2023	9.485
2024	9.562
2025	9.639
2026	9.717
2027	9.794
2028	9.871
2029	9.948
2030	10.025
