Year	% of output
1971	7.518796992481203
1972	6.928104575163399
1973	6.746987951807229
1974	8.093278463648835
1975	6.564245810055866
1976	5.9045226130653266
1977	5.813953488372093
1978	5.8759521218716
1979	5.424769703172978
1980	6.189555125725339
1981	6.60377358490566
1982	7.080419580419581
1983	5.896805896805897
1984	6
1985	5.761940864291129
1986	6.2543921293042875
1987	5.9960026648900735
1988	6.49666059502125
1989	5.843801201529219
1990	5.623100303951368
1991	6.451612903225806
1992	6.502057613168724
1993	5.019305019305019
1994	4.655493482309125
1995	4.60552663195835
1996	5.711000383288616
1997	6.341642228739003
1998	5.884319625543297
1999	6.244026760114687
2000	5.578635014836795
2001	6.561531962827373
2002	4.41215323645971
2003	3.923988153998026
2004	5.07022137586289
2005	3.7468585789353437
2006	4.750644883920894
2007	4.413878053787723
2008	3.0124040165386887
2009	3.6241610738255035
2010	4.133784291619691
2011	3.2460945425035503
2012	2.90438838244647
2013	4.335664335664335
2014	3.977011494252874