Year	% of output
1971	5.609284332688588
1972	6.138676844783715
1973	5.700457112126916
1974	5.693581780538302
1975	6.369731800766283
1976	6.145494028230185
1977	5.728250244379277
1978	4.679552390640895
1979	5.800892444991537
1980	4.820483478758404
1981	5.084745762711865
1982	5.243209096651927
1983	5.549172794117647
1984	5.5005268703898835
1985	4.889558232931726
1986	5.112781954887218
1987	4.735914014610799
1988	4.522229848242203
1989	3.812959818902094
1990	3.372788596156294
1991	5.419301459724603
1992	4.277469729546226
1993	3.6177618394684106
1994	4.187251187107295
1995	3.834741952886172
1996	3.8506224066390047
1997	3.6210870696706072
1998	3.591189427312776
1999	3.6111111111111107
2000	3.6380862150639506
2001	6.005016772945692
2002	6.560120009231479
2003	5.507755009623005
2004	5.8895438863383225
2005	3.1245911077382043
2006	2.692561229146595
2007	2.873605134563489
2008	2.543327660186495
2009	1.7908709262539735
2010	2.854875333436212
2011	2.5424833760702334
2012	1.8969151178386663
2013	2.2952323375513353
2014	2.029161603888214
