Year	%
1988	55.96867
1989	68.81251
1990	52.29332
1991	58.33631
1992	69.90418
1993	58.91507
1994	61.81646
1995	49.06126
1996	34.96623
1997	36.47451
1998	26.21992
1999	37.05973
2000	26.70334
2001	27.47944
2002	18.27956
2003	25.09445
2004	17.15631
2005	17.29718
2006	16.60014
2007	21.34557
2008	15.23083
2009	16.2457
2010	14.47838
2011	14.43611
2012	11.20571
2013	16.75973
2014	17.36528
2015	15.0047
2016	14.02434
2017	15.9274