Year	Percent
1990	11.251
1991	11.507
1992	11.853
1993	12.23
1994	11.319
1995	10.468
1996	9.674
1997	8.934
1998	8.245
1999	7.605
2000	7.011
2001	6.46
2002	5.95
2003	5.976
2004	6.058
2005	5.974
2006	6.01
2007	6.063
2008	5.999
2009	5.983
2010	6.024
2011	6.037
2012	6.061
2013	6.112
2014	6.143
2015	6.163
2016	6.225
2017	6.18
2018	6.134
2019	6.088
2020	6.042
2021	5.996
2022	5.95
2023	5.904
2024	5.858
2025	5.812
2026	5.767
2027	5.721
2028	5.675
2029	5.629
2030	5.583