Year	Percent
1990	2.333
1991	2.356
1992	2.359
1993	2.397
1994	2.428
1995	2.352
1996	2.287
1997	2.265
1998	2.333
1999	2.389
2000	2.363
2001	2.394
2002	2.447
2003	2.419
2004	2.353
2005	2.375
2006	2.387
2007	2.389
2008	2.441
2009	2.611
2010	2.562
2011	2.468
2012	2.497
2013	2.517
2014	2.562
2015	2.62
2016	2.666
2017	2.676
2018	2.687
2019	2.698
2020	2.708
2021	2.719
2022	2.73
2023	2.741
2024	2.751
2025	2.762
2026	2.773
2027	2.783
2028	2.794
2029	2.805
2030	2.815