Year	Percent
1990	2.235
1991	2.234
1992	2.204
1993	2.229
1994	2.247
1995	2.248
1996	2.257
1997	2.24
1998	2.259
1999	2.278
2000	2.297
2001	2.317
2002	2.336
2003	2.356
2004	2.376
2005	2.339
2006	2.302
2007	2.266
2008	2.23
2009	2.222
2010	2.166
2011	2.101
2012	1.937
2013	1.897
2014	1.969
2015	1.985
2016	1.868
2017	1.847
2018	1.826
2019	1.805
2020	1.784
2021	1.762
2022	1.741
2023	1.72
2024	1.699
2025	1.678
2026	1.657
2027	1.635
2028	1.614
2029	1.593
2030	1.572