Year	Percent
1960	0.14231
1961	2.7473
1962	10.04159
1963	6.39151
1964	19.38846
1965	19.19727
1966	16.08769
1967	15.88036
1968	19.64744
1969	18.68255
1970	16.05887
1971	14.78703
1972	12.50554
1973	10.88993
1974	11.18752
1975	11.40561
1976	10.02547
1977	6.07045
1978	5.50956
1979	6.25454
1980	7.76975
1981	5.62526
1982	7.77519
1983	12.3358
1984	15.4296
1985	12.98658
1986	15.78742
1987	19.3542
1988	32.73915
1989	45.4146
1990	95.05435
1991	81.58822
1992	97.86086
1993	70.59411
1994	139.76586
1995	70.66111
1996	41.00642
1997	14.98489
1998	24.31962
1999	16.22273
2000	13.31983
2001	7.78409
2002	49.17623
2003	8.54629
2004	4.64432
2005	2.74343
2006	6.89351
2007	4.33368
2008	9.43647
2009	48.09753
2010	11.15986
2011	23.61217
2012	39.17435
2013	12.99942
2014	8.37253
2015	6.08218
2016	5.48447
2017	7.58482
2018	7.37233
2019	8.97434
2020	12.54476
2021	10.10979