Year	Percent
1990	15.43
1991	17.559
1992	19.914
1993	22.497
1994	25.31
1995	25.558
1996	25.538
1997	25.502
1998	25.664
1999	25.9
2000	26.095
2001	26.3
2002	26.487
2003	26.586
2004	26.521
2005	26.584
2006	26.487
2007	26.154
2008	26.319
2009	26.433
2010	26.633
2011	26.786
2012	26.82
2013	26.589
2014	26.695
2015	26.896
2016	27.073
2017	27.096
2018	27.119
2019	27.142
2020	27.165
2021	27.188
2022	27.211
2023	27.234
2024	27.257
2025	27.28
2026	27.304
2027	27.327
2028	27.35
2029	27.373
2030	27.396