Year	Percent
1971	7.11338
1972	5.2277
1973	16.25528
1974	12.98966
1975	9.46099
1976	9.17211
1977	8.89635
1978	11.85602
1979	9.17443
1980	6.80427
1981	9.50226
1982	4
1983	5.84677
1984	6.73993
1985	5.1521
1986	5.21739
1987	10.09174
1988	4.95448
1989	-2.16601
1990	-1.06275
1991	19.60784
1992	5.63079
1993	5.23873
1994	6.85335
1995	1.33333
1996	9.97807
1997	5.30376
1998	7.25275
1999	4.49219
2000	2.03408
2001	6.74215
2002	4.94713
2003	2.6393
2004	1.70764
2005	0.51207
2006	-0.25552
2007	6.06979
2008	8.14137
2009	0.56323
2010	1.52376
2011	2.28775
2012	0.53458
2013	0.90464
2014	1.45858
2015	2.86665
2016	7.25172
2017	1.64246