Year	%
1988	6.07
1989	6.06
1990	8.51
1991	7.01
1992	7.11
1993	7.06
1994	7
1995	6.57
1996	5.63
1997	5.75
1998	5.14
1999	4.72
2000	4.54
2001	4.6
2002	4.77
2003	4.53
2004	4.26
2005	4.26
2006	4.25
2007	4.03
2008	4.03
2009	4.02
2010	4.22
2011	4.21
2012	4.2
2013	4.19
2014	4.18
2015	4.19
2016	4.13
2017	4.14
2018	4.12
2019	4.1
2020	3.96
2021	4.1