Year	Percent
1975	29.00433
1976	20.30709
1978	11.20159
1979	8.12506
1980	7.13586
1981	8.24589
1982	5.71364
1983	6.37027
1984	7.70952
1985	10.82025
1986	19.52057
1987	22.36371
1988	24.2321
1989	29.65256
1990	20.82764
1991	25.6809
1992	18.47166
1993	22.66169
1994	29.29084
1995	31.09124
1996	37.602
1997	49.3268
1998	65.1759
1999	68.05181
2000	84.68544
2001	74.79573
2002	65.45587
2003	80.08389
2004	87.94989
2005	82.94564
2006	104.61538
2007	121.66453
2008	58.00265
2009	95.69346
2010	81.83929
2011	69.28367
2012	74.48161
2013	81.98829
2014	72.11169
2015	65.7204
2016	56.94471
2017	67.7819