Year	Percent
1961	3.75753
1962	0.91188
1963	6.19158
1964	6.63366
1965	4.49327
1966	9.20293
1967	6.59852
1968	10.59249
1969	11.97779
1970	7.62092
1971	8.2986
1972	5.15931
1973	12.81491
1974	7.60209
1975	6.06442
1976	11.32355
1977	10.54078
1978	9.10433
1979	6.99035
1980	-3.22135
1981	5.52125
1982	6.60468
1983	11.58487
1984	9.0884
1985	6.69399
1986	10.1232
1987	11.36475
1988	10.81431
1989	5.9763
1990	8.73476
1991	9.26707
1992	5.07788
1993	5.76687
1994	8.11287
1995	8.47363
1996	6.57424
1997	4.93358
1998	-6.15113
1999	10.52025
2000	8.01742
2001	3.72641
2002	6.81331
2003	2.40107
2004	4.48491
2005	3.70359
2006	4.62522
2007	4.9319
2008	2.05138
2009	0.19052
2010	5.96752
2011	2.88746
2012	1.75604
2013	2.42887
2014	2.69434
2015	2.24966
2016	2.46581
2017	2.62122