Year	Percent
1970	2.21773
1971	0.89616
1972	1.3725
1973	2.74671
1974	4.02836
1975	4.23403
1976	7.51796
1977	11.77745
1978	14.07241
1979	14.10372
1980	15.10712
1981	13.88142
1982	15.39313
1983	16.2094
1984	18.26212
1985	21.41715
1986	23.33329
1987	28.23528
1988	27.44126
1989	26.02337
1990	28.04027
1991	42.61268
1992	42.45472
1993	46.46271
1994	127.41484
1995	79.48606
1996	76.3931
1997	60.64396
1998	62.32518
1999	72.64754
2000	75.01704
2001	78.61551
2002	87.59479
2003	85.66414
2004	81.2768
2005	59.75423
2006	13.88302
2007	16.25943
2008	14.27542
2009	16.12315
2010	15.81387
2011	18.89686
2012	17.48351
2013	22.62176
2014	25.7977
2015	27.79959
2016	34.08812