Year	Percent
1990	16.33
1991	15.7
1992	16.09
1993	15.57
1994	16.84
1995	16.76
1996	16.86
1997	17.06
1998	16.45
1999	16.93
2000	17.72
2001	17.74
2002	17.86
2003	18.57
2004	18.98
2005	19.8
2006	20.34
2007	20.53
2008	21.47
2009	21.92
2010	22.07
2011	22.83
2012	23.59
2013	23.49
2014	22.97
2015	23.39
2016	23.97
2017	24.181
2018	24.391
2019	24.602
2020	24.812
2021	25.023
2022	25.233
2023	25.444
2024	25.654
2025	25.865
2026	26.076
2027	26.286
2028	26.497
2029	26.707
2030	26.918