Year	% of output
1971	19.971056439942114
1972	20.70773263433814
1973	18.879415347137638
1974	20.56737588652482
1975	20.858895705521473
1976	21.336996336996336
1977	20.067170445004198
1978	17.940466613032985
1979	17.91044776119403
1980	21.856086079354405
1981	23.655913978494624
1982	25.773195876288657
1983	28.83582089552239
1984	30.52910052910053
1985	24.728645587541294
1986	27.57238307349666
1987	28.23275862068966
1988	32.47978436657682
1989	34.322373696872496
1990	26.432606941081517
1991	36.047814717967874
1992	37.416555407209614
1993	35.805022156573116
1994	34.83583750695603
1995	38.10110974106042
1996	35.057034220532316
1997	34.69066366704162
1998	28.509301763711044
1999	32.20521664151757
2000	31.30128956623681
2001	31.13670292173171
2002	31.254932912391475
2003	29.05069124423963
2004	30.29060438580852
2005	39.09574468085106
2006	29.347826086956523
2007	30.62978590404751
2008	29.009362730292963
2009	28.302699597932225
2010	16.61142781386716
2011	20.226996351844345
2012	25.260901975400675
2013	21.515473177104596
2014	20.49162958253867