Year	Percent
1965	44.59279
1966	41.33489
1967	31.07798
1968	35.64669
1969	34.58038
1970	35.70106
1971	47.68418
1972	47.93716
1973	49.76622
1974	71.11723
1975	54.45942
1976	45.37854
1977	28.58342
1978	30.67326
1979	49.15349
1980	44.05115
1981	31.02007
1982	2.14091
1983	9.7772
1984	15.47185
1985	10.93034
1986	-1.82593
1987	15.41712
1988	4.62481
1989	11.03193
1990	-13.1331
1991	-108.80888
1992	-13.74753
1993	3.48534
1994	8.52303
1995	10.38945
1996	13.09747
1997	13.26237
1998	-7.234
1999	6.50009
2000	26.32671
2001	15.76488
2002	8.0069
2003	17.62809
2004	24.53616
2005	35.70974
2006	41.37767
2007	35.09714
2008	40.83544
2009	30.07415
2010	36.31901
2011	47.31885
2012	48.45225
2013	44.11637
2014	36.97534
2015	8.83089
2016	1.80323