Year	% of output
1971	16.36237647625934
1972	17.343581598502468
1973	17.764712346832244
1974	17.418294686872375
1975	16.905244047203407
1976	17.200230089421115
1977	16.71114345786835
1978	17.579384176738188
1979	17.794559523492968
1980	17.71047014758033
1981	17.82588982090229
1982	18.12456708273844
1983	18.223041232024745
1984	18.16023876984658
1985	18.375374826693033
1986	18.278088551803933
1987	19.03229586364169
1988	18.21627373935822
1989	19.593993039460226
1990	19.30810434117213
1991	19.244117573358057
1992	18.25873937143552
1993	18.016322797877205
1994	17.80084081133432
1995	18.7327101921352
1996	20.564023736487965
1997	20.71579383851163
1998	22.130774926501388
1999	25.6816974183264
2000	27.220689219362175
2001	28.241956845883255
2002	26.680010876295245
2003	26.740182257615963
2004	25.66334937155606
2005	25.16558234682585
2006	23.655567962118628
2007	22.768507084461056
2008	21.255370687978502
2009	21.12673906739547
2010	19.862550744525308
2011	19.394417683539686
2012	18.897750676951762
2013	18.494196239646936
2014	19.330407318027152