Year	Percent
1960	-8.07175
1961	-5.77778
1962	-9.09091
1963	-3.52941
1964	-0.72993
1965	-0.98684
1966	-5
1967	-1.18694
1968	-2.14477
1969	-3.59712
1970	-2.00501
1993	-16.61011
1994	-12.88411
1995	-15.39836
1996	-18.43355
1997	-11.70077
1998	-13.14318
1999	-13.08852
2000	-11.83973
2001	-8.66098
2002	-8.84867
2003	-10.03987
2004	-7.29963
2005	-8.66252
2006	-7.42796
2007	-7.61621
2008	-2.23376
2009	-6.69695
2010	-5.43815
2011	-5.42033
2012	-4.81791
2013	-5.27062
2014	-4.40528
2015	-4.42722
2016	-4.38698
2017	-3.42679