Year	Percent
1990	5.09
1991	5.11
1992	5.15
1993	4.49
1994	4.29
1995	4.052
1996	3.827
1997	3.614
1998	3.412
1999	3.221
2000	3.041
2001	2.87
2002	2.59
2003	2.73
2004	2.73
2005	2.9
2006	3.08
2007	3.43
2008	3.83
2009	4.41
2010	3.966
2011	3.712
2012	4.038
2013	4.085
2014	3.958
2015	3.869
2016	3.918
2017	4.03
2018	4.142
2019	4.254
2020	4.367
2021	4.479
2022	4.591
2023	4.703
2024	4.816
2025	4.928
2026	5.04
2027	5.152
2028	5.264
2029	5.377
2030	5.489