Year	% of output
1971	8.62453531598513
1972	9.265387160820648
1973	9.838369641602249
1974	8.956109134045077
1975	10.497237569060774
1976	13.478260869565217
1977	17.979062357760583
1978	16.19644723092999
1979	16.762839007501444
1980	17.9040404040404
1981	17.56325749521582
1982	15.207678305477412
1983	14.207419898819563
1984	15.143638850889193
1985	14.877184097239807
1986	14.328884411986905
1987	14.394792840155212
1988	23.444976076555022
1989	21.769488283118125
1990	26.164843682714668
1991	26.28294605468429
1992	26.26970227670753
1993	26.230416205095743
1994	30.951126333816358
1995	28.152827918170882
1996	28.15004634425604
1997	28.900164001640015
1998	29.349213100808168
1999	28.905736447697095
2000	30.697545306737517
2001	28.182090446241393
2002	24.767072430657194
2003	22.83885822639082
2004	20.616017707391592
2005	19.37025905252612
2006	19.284928787919426
2007	21.810465296827285
2008	21.368500597225946
2009	25.63729564976448
2010	15.303901924029905
2011	15.432393693263258
2012	15.208962882718513
2013	13.944814309777815
2014	15.915887406844828