Year	Percent
1978	17.27327
1979	9.62162
1980	9.04925
1981	2.70871
1982	4.16359
1983	1.39348
1984	6.61239
1985	8.7481
1986	4.33505
1987	5.05935
1988	6.76145
1989	8.99639
1990	0.01594
1991	6.6699
1992	4.01158
1993	1.88342
1994	3.19076
1995	3.05315
1996	2.67308
1997	1.78471
1998	1.74744
1999	1.11198
2000	2.86303
2001	2.14418
2002	0.37215
2003	-0.07707
2004	2.03115
2005	2.46527
2006	4.65758
2007	2.31997
2008	7.84636
2009	-0.00912
2010	0.47972
2011	0.22343
2012	3.92764
2013	2.922
2014	0.77243
2015	2.76712
2016	2.17203
2017	2.12022