Year	Percent
1990	21.057
1991	21.954
1992	22.249
1993	22.562
1994	23.127
1995	23.118
1996	23.713
1997	24.18
1998	24.646
1999	25.14
2000	25.735
2001	26.124
2002	26.546
2003	27.455
2004	28.059
2005	28.939
2006	29.517
2007	30.06
2008	30.402
2009	30.553
2010	30.985
2011	27.752
2012	29.897
2013	28.562
2014	27.388
2015	27.289
2016	27.35
2017	27.374
2018	27.38
2019	27.367
2020	27.339
2021	27.303
2022	27.256
2023	27.202
2024	27.145
2025	27.089
2026	27.041
2027	26.995
2028	26.958
2029	26.941
2030	26.947