Year	%
1988	3.47
1989	3.32
1990	3.55
1991	3.89
1992	4.19
1993	4.15
1994	4.12
1995	9.96
1996	8.74
1997	7.35
1998	7.42
1999	7.39
2000	4.74
2001	5.34
2002	4.18
2003	4.66
2004	3.91
2005	3.58
2006	3.06
2007	3.02
2008	2.49
2009	3
2010	2.6
2011	2.44
2012	2.15
2013	2.4
2014	2.58
2015	2.61
2016	3.21
2017	3.05
2018	2.62
2019	2.72
2020	2.18
2021	2.84