Year	% of output
1971	4.8
1972	4.8
1973	4.471544715447155
1974	4.3999999999999995
1975	4.3999999999999995
1976	4.3999999999999995
1977	4.3999999999999995
1978	4.3999999999999995
1979	4.3999999999999995
1980	4.373177842565598
1981	4.2283298097251585
1982	4.232804232804233
1983	4.252199413489736
1984	4.266666666666667
1985	4.308093994778068
1986	4.375804375804376
1987	4.414587332053743
1988	4.47080291970803
1989	4.5053003533568905
1990	4.522184300341297
1991	6.1465721040189125
1992	6.183368869936034
1993	4.1343669250646
1994	2.8863499699338546
1995	3.5096642929806716
1996	2.025435704192181
1997	1.2048192771084338
1998	1.15814696485623
1999	1.1503697617091209
2000	1.1403853716083368
2001	5.312136487010469
2002	5.33135875601629
2003	5.3274835474772795
2004	5.330882352941177
2005	5.330882352941177
2006	5.336567616737416
2007	4.860088365243005
2008	4.79111890154835
2009	6.035437430786268
2010	9.70464135021097
2011	7.16778523489933
2012	6.183206106870228
2013	9.291231258518854
2014	6.413670661340435