Year	Percent
1961	20.3107
1962	28.87184
1963	25.59115
1964	28.77462
1965	21.23293
1966	25.60346
1967	29.01826
1968	10.27531
1969	7.79583
1970	6.46787
1971	31.27106
1972	64.24479
1973	65.53529
1974	30.63044
1975	197.69736
1976	438.32278
1977	159.42718
1978	161.37217
1979	147.37704
1980	90.8408
1981	106.3641
1982	207.61768
1983	382.34943
1984	606.73594
1985	625.80214
1986	74.46149
1987	127.08638
1988	388.49134
1989	3057.62884
1990	2076.79347
1991	132.95323
1992	11.92076
1993	-1.46666
1994	2.84934
1995	3.16512
1996	-0.05238
1997	-0.46391
1998	-1.70528
1999	-1.83656
2000	1.03729
2001	-1.09577
2002	30.5552
2003	10.4957
2004	18.36335
2005	10.31751
2006	13.74105
2007	14.93993
2008	23.17116
2009	15.37765
2010	20.91512
2011	23.70347
2012	22.31488
2013	23.9488
2014	40.28297
2015	26.57999
2016	40.07469
2017	25.34918