Year	%
1989	4.78
1990	4.88
1991	4.93
1992	5.01
1993	4.9
1995	4.32
1996	4.13
1997	4
1998	3.55
1999	3.29
2000	3.15
2001	3.28
2002	3.25
2003	3.13
2004	2.89
2005	2.81
2006	2.76
2007	2.12
2008	2.57
2009	2.62
2010	2.61
2011	2.56
2012	2.55
2013	2.61
2014	2.61
2015	2.64
2016	2.64
2017	2.39
2018	2.56
2019	3.23
2020	2.44
2021	2.51