Year	Percent
1990	6.77
1991	6.758
1992	6.713
1993	6.626
1994	6.554
1995	6.499
1996	6.423
1997	6.378
1998	6.345
1999	6.303
2000	6.234
2001	6.192
2002	6.131
2003	6.058
2004	5.986
2005	5.921
2006	5.863
2007	5.807
2008	5.754
2009	5.701
2010	5.647
2011	5.593
2012	5.544
2013	5.497
2014	5.453
2015	5.408
2016	5.375
2017	5.328
2018	5.282
2019	5.235
2020	5.188
2021	5.142
2022	5.095
2023	5.048
2024	5.002
2025	4.955
2026	4.908
2027	4.861
2028	4.815
2029	4.768
2030	4.721