Year	% of output
1971	14.960629921259844
1972	15.5
1973	15.384615384615385
1974	14.888888888888888
1975	14.40501043841336
1976	14.619883040935672
1977	16.049382716049383
1978	16.612903225806452
1979	17.75147928994083
1980	14.940828402366865
1981	14.586255259467041
1982	16
1983	14.285714285714285
1984	14.49814126394052
1985	16.064757160647574
1986	15.355805243445692
1987	17.803468208092486
1988	16.835016835016837
1989	20.195439739413683
1990	17.46031746031746
1991	17.853457172342623
1992	17.015209125475288
1993	17.1648987463838
1994	12.990654205607477
1995	16.07773851590106
1996	18.453865336658353
1997	16.886134779240898
1998	15.657311669128507
1999	19.027181688125893
2000	37.34413965087282
2001	33.9323467230444
2002	25.88062622309198
2003	37.43016759776536
2004	32.99469964664311
2005	30.14937106918239
2006	25.543255432554325
2007	19.01355421686747
2008	30.55355859094177
2009	16.969909027291813
2010	16.38491547464239
2011	15.709298635353855
2012	16.28985507246377
2013	16.652625666947486
2014	12.866756393001348