Year	%
1988	9.495543
1989	3.596448
1990	18.86574
1991	19.49218
1992	21.59738
1993	7.020109
1994	27.25984
1995	10.73159
1996	13.60011
1997	15.98989
1998	9.855646
1999	9.906983
2000	9.714107
2001	11.40267
2002	10.32675
2003	7.487861
2004	9.081004
2005	9.701259
2006	7.019845
2007	12.63583
2008	13.62133
2009	12.24916
2010	8.198862
2011	11.21679
2012	5.599475
2013	11.65394
2014	10.30409
2015	8.181141
2016	6.29827
2017	5.786465