Year	% of output
1971	15.384615384615385
1972	14.916467780429594
1973	15.205327413984463
1974	14.358452138492872
1975	11.775528978840846
1976	13.291634089132135
1977	6.78513731825525
1978	13.425925925925927
1979	13.094539048737522
1980	14.60122699386503
1981	13.473684210526315
1982	14.519427402862986
1983	14.264919941775837
1984	13.162878787878787
1985	13.33907056798623
1986	13.491743858236005
1987	12.940761636107192
1988	16.0472972972973
1989	14.696382428940568
1990	15.023183925811438
1991	14.764123471170645
1992	14.873140857392825
1993	15.652654867256638
1994	15.542201584266593
1995	18.332925934979222
1996	17.871345029239766
1997	21.108884435537743
1998	20.463404071026417
1999	21.652743282908105
2000	21.64253619570644
2001	20.934869295525033
2002	22.650032265003226
2003	20.878459687123947
2004	18.029428198919724
2005	18.983634797588287
2006	17.58521822236381
2007	16.39141842876987
2008	16.063829787234045
2009	15.763837638376385
2010	15.958885582905058
2011	17.137330754352032
2012	18.452308069058407
2013	17.981072555205046
2014	17.552387124648952