Year	Percent
1990	12.48
1991	12.362
1992	12.425
1993	12.582
1994	13.024
1995	13.331
1996	13.631
1997	13.853
1998	14.119
1999	14.209
2000	14.506
2001	14.559
2002	14.744
2003	14.934
2004	15.283
2005	15.757
2006	16.328
2007	17.061
2008	17.715
2009	18.206
2010	19.027
2011	20.137
2012	21.3
2013	22.511
2014	23.794
2015	25.128
2016	26.132
2017	26.29
2018	26.449
2019	26.608
2020	26.766
2021	26.925
2022	27.083
2023	27.242
2024	27.401
2025	27.559
2026	27.718
2027	27.877
2028	28.035
2029	28.194
2030	28.352