Year	%
1988	44.28158
1989	92.25629
1990	52.38913
1991	41.53716
1992	58.82654
1993	34.35955
1994	37.60997
1995	24.98272
1996	27.56806
1997	28.61742
1998	25.98323
1999	26.37676
2000	30.32268
2001	26.9486
2002	24.335
2003	28.80885
2004	22.1499
2005	19.32935
2006	16.90462
2007	22.04078
2008	23.54848
2009	22.14171
2010	17.00397
2011	20.01059
2012	13.33386
2013	19.26407
2014	15.77459
2015	15.82041
2016	15.14324
2017	15.22424