Year	%
1988	23.59
1989	23.58
1990	14.98
1992	14.94
1993	15.3
1994	15.02
1995	14.25
1996	7.58
1997	6.93
1998	5.85
1999	5.64
2000	3.14
2001	2.79
2002	1.85
2003	1.84
2004	1.93
2005	1.92
2006	1.87
2007	1.87
2008	3.87
2009	3.73
2010	3.72
2011	1.8
2012	1.64
2013	1.64
2015	1.54
2016	4
2017	1.41
2018	1.28
2019	1.02
2020	1.01
2021	0.87