Year	% of output
1971	17.569630916653505
1972	18.344552480678136
1973	18.47047018348624
1974	18.116679098573723
1975	17.885972997336196
1976	18.404570422470634
1977	18.042462207221934
1978	18.72555075149269
1979	18.83079739160279
1980	19.19482026342742
1981	18.878566905385203
1982	19.041167464579942
1983	19.09511793993737
1984	19.0949607470292
1985	18.85908799091039
1986	18.63078976060079
1987	19.596295197092278
1988	19.00116588650878
1989	19.826683653518675
1990	19.761518565604312
1991	19.664209422623628
1992	18.91883769793469
1993	18.621316748471013
1994	18.392162750870963
1995	19.149573500113586
1996	20.759712041834415
1997	21.007585826529596
1998	22.8712007253045
1999	25.502554989884196
2000	26.552387510230457
2001	27.536223441361642
2002	26.190726262146732
2003	26.079972470388594
2004	24.924467921227993
2005	24.397791854306746
2006	22.88405473551505
2007	21.83593271313772
2008	20.908484852169085
2009	20.645438064532517
2010	19.204340957239907
2011	18.83518087700754
2012	18.440541494666803
2013	18.07862208951021
2014	18.8367793271604