Year	Percent
1960	126.33933
1961	113.4921
1962	46.63463
1963	34.33864
1964	51.74515
1965	75.49606
1966	51.8102
1967	54.6286
1968	50.3189
1969	56.85252
1970	23.14989
1971	7.58933
1972	27.76331
1973	23.37692
1974	22.71819
1975	27.00079
1976	21.93751
1977	33.54909
1978	26.62622
1979	27.55034
1980	21.84911
1981	19.8711
1982	16.24318
1983	17.78824
1984	20.38193
1985	25.39037
1986	36.74126
1987	50.16914
1988	23.4833
1989	17.78432
1990	31.83254
1991	29.24916
1992	22.10952
1993	22.12092
1994	23.45816
1995	21.21371
1996	12.10679
1997	9.62191
1998	11.60495
1999	11.29234
2000	3.20914
2001	7.97655
2002	7.22626
2003	8.06581
2004	4.08497
2005	8.4703
2006	6.41454
2007	9.10572
2008	13.53891
2009	10.12716
2010	14.17833
2011	19.9616
2012	15.51022
2013	20.9635
2014	15.50416
2015	18.21625
2016	30.13213
2017	26.1288
2018	19.62528
2019	11.56251
2020	21.49927
2021	18.9181