Year	Percent
1988	1.44
1989	1.08
1990	1.45
1991	1.24
1992	0.95
1993	0.45
1994	1.09
1995	1.09
1996	0.73
1997	0.75
1998	0.91
1999	0.73
2000	0.53
2001	0.79
2002	0.86
2003	0.59
2004	1.1
2005	0.66
2006	0.65
2007	0.46
2008	0.78
2009	1.1
2010	1.28
2011	0.86
2012	0.85
2013	1
2014	2.03
2015	2.34
2016	2.49
2017	2.05
2018	2.67
2019	3
2020	2.71