Year	%
1991	19.01661
1995	18.20725
1996	19.43039
1997	19.71573
1998	19.97552
1999	23.03975
2000	49.4489
2001	50.10233
2002	43.32745
2003	50.22941
2004	28.30752
2005	12.0321
2006	10.51519
2007	9.692602
2008	10.86549
2009	10.93781
2010	4.937914
2011	5.131635
2012	5.007938
2013	4.934943
2014	7.594971
2015	4.590657
2016	4.97151
2017	8.462452
2018	5.621659