Year	Percent
1961	18.42688
1962	11.99062
1963	19.89871
1964	40.35152
1965	62.18479
1966	72.31778
1967	78.52849
1968	116.24917
1969	27.08023
1970	4.18747
1971	31.68997
1972	69.16707
1973	191.57412
1974	28.48704
1975	65.97788
1976	47.29149
1977	55.60669
1978	46.80166
1979	79.20819
1980	54.7627
1981	27.3446
1982	18.16227
1983	53.73105
1984	56.34961
1985	74.01716
1986	70.96334
1987	72.78399
1988	74.63639
1989	76.07947
1990	106.83668
1991	100.80817
1992	59.62362
1993	47.85193
1994	38.95718
1995	41.04833
1996	26.43174
1997	27.48517
1998	12.38391
1999	4.3261
2000	3.53931
2001	4.82662
2002	12.61628
2003	16.54164
2004	10.10506
2005	0.67787
2006	6.53333
2007	9.41747
2008	8.02354
2009	7.74754
2010	4.90703
2011	9.00968
2012	8.55755
2013	8.15373
2014	9.37225
2015	9.01628
2016	7.34549
2017	4.0247