Year	%
1988	2.73
1989	2.71
1990	3.03
1991	3.04
1992	3.21
1993	2.57
1994	2.65
1995	8.81
1996	7.09
1997	5.12
1998	5.48
1999	5.61
2000	3.14
2001	4.8
2002	2.92
2003	3.35
2004	2.77
2005	2.63
2006	2.06
2007	2.04
2008	1.56
2009	1.87
2010	1.55
2011	1.4
2012	1.19
2013	1.33
2014	1.69
2015	1.69
2016	2.1
2017	1.84
2018	1.59
2019	1.64
2020	0.83
2021	1.34