Year	%
1988	5.17
1989	4.99
1990	4.18
1991	4.18
1992	4.2
1993	4.27
1994	4.3
1995	3.74
1996	3.99
1997	3.36
1998	3.26
1999	3.11
2000	3.06
2001	2.97
2002	2.91
2003	2.8
2004	2.69
2005	2.68
2006	2.93
2007	2.88
2008	2.86
2009	2.87
2010	2.88
2011	2.92
2012	2.83
2013	2.43
2014	2.77
2015	2.67
2016	2.75
2017	2.75
2018	2.77
2019	3.22
2020	2.76
2021	2.74