Year	Percent
1990	22.546
1991	22.356
1992	22.598
1993	22.634
1994	22.812
1995	22.87
1996	23.04
1997	22.498
1998	21.965
1999	21.442
2000	20.927
2001	20.422
2002	19.925
2003	19.438
2004	18.96
2005	18.491
2006	18.031
2007	17.58
2008	16.929
2009	16.297
2010	15.685
2011	15.091
2012	14.516
2013	13.959
2014	13.42
2015	13.515
2016	13.539
2017	13.279
2018	13.02
2019	12.76
2020	12.501
2021	12.241
2022	11.982
2023	11.722
2024	11.462
2025	11.203
2026	10.943
2027	10.684
2028	10.424
2029	10.165
2030	9.905