Year	%
1991	19.37467
1995	18.47846
1996	19.85844
1997	20.37435
1998	20.54653
1999	22.68961
2000	49.26822
2001	49.8738
2002	42.87342
2003	50.06002
2004	28.1688
2005	12.35272
2006	10.88665
2007	10.21535
2008	11.38522
2009	11.3797
2010	6.127679
2011	6.580734
2012	6.40132
2013	6.088978
2014	7.963817
2015	5.724122
2016	6.290119
2017	8.868709
2018	5.987799