Year	Percent
1990	27.805
1991	27.764
1992	27.918
1993	28.002
1994	28.102
1995	28.187
1996	28.257
1997	28.313
1998	28.366
1999	28.463
2000	28.56
2001	28.617
2002	28.653
2003	28.664
2004	28.642
2005	28.587
2006	28.502
2007	28.397
2008	28.286
2009	28.153
2010	28.015
2011	27.932
2012	27.813
2013	27.665
2014	27.514
2015	27.37
2016	27.241
2017	27.174
2018	27.106
2019	27.039
2020	26.971
2021	26.904
2022	26.836
2023	26.769
2024	26.701
2025	26.634
2026	26.566
2027	26.499
2028	26.432
2029	26.364
2030	26.297