Year	Percent
1960	25.89686
1961	24.88889
1962	23.63636
1963	26.90196
1964	21.71533
1965	23.94737
1966	19.46875
1967	18.5905
1968	19.23593
1969	16.95827
1970	12.94541
1971	7.01095
1972	17.209
1973	23.47421
1974	33.81801
1993	29.79799
1994	44.20665
1995	59.33967
1996	48.93496
1997	52.27371
1998	63.00423
1999	77.33331
2000	90.48647
2001	90.19996
2002	98.99561
2003	100.42276
2004	112.24199
2005	111.52786
2006	116.34488
2007	110.28001
2008	108.35127
2009	96.39309
2010	106.15242
2011	124.74442
2012	136.52694
2013	106.52157
2014	105.00103
2015	113.09537
2016	113.41
2017	117.02209