Year	Percent
1990	9.21
1991	7.59
1992	6.75
1993	6.55
1994	5.75
1995	5.5
1996	4.36
1997	5.11
1998	3.92
1999	3.79
2000	4.3
2001	4.22
2002	3.98
2003	4.74
2004	4.01
2005	4.51
2006	4.87
2007	6.26
2008	6.54
2009	5.98
2010	6.58
2011	7.18
2012	7.92
2013	7.68
2014	8.57
2015	9
2016	8.5
2017	8.733
2018	8.966
2019	9.199
2020	9.432
2021	9.665
2022	9.897
2023	10.13
2024	10.363
2025	10.596
2026	10.829
2027	11.062
2028	11.295
2029	11.528
2030	11.761