Year	%
1988	4.73
1989	4.73
1990	5.97
1991	5.68
1992	6.06
1993	5.97
1994	5.87
1995	7.38
1996	6.07
1997	5.67
1998	4.86
1999	4.52
2000	3.75
2001	4.07
2002	3.91
2003	4.01
2004	3.64
2005	3.54
2006	3.33
2007	3.23
2008	2.99
2009	3.23
2010	3.08
2011	3
2012	2.84
2013	2.95
2014	3.07
2015	3.09
2016	3.29
2017	3.27
2018	3.11
2019	3.08
2020	2.8
2021	2.85