Year	% of output
1971	15.11627906976744
1972	16.822429906542055
1973	28.846153846153843
1974	26.785714285714285
1975	37.5
1976	27.27272727272727
1977	26.751592356687897
1978	28.735632183908045
1979	30.05181347150259
1980	21.19815668202765
1981	21.34387351778656
1982	21.296296296296298
1983	20.891364902506965
1984	21.502590673575128
1985	21.627906976744185
1986	20.51756007393715
1987	21.808510638297875
1988	23.28767123287671
1989	21.089385474860336
1990	18.906605922551254
1991	19.313304721030043
1992	20.767494356659142
1993	21.114683815648448
1994	21.485148514851485
1995	19.732441471571907
1996	20.884520884520885
1997	22.412318220701454
1998	22.720000000000002
1999	21.853856562922868
2000	21.217600964436407
2001	20.9962506695233
2002	19.64201601507301
2003	19.49713277459197
2004	27.129859387923904
2005	28.345834978286614
2006	29.65793304221252
2007	30.26504297994269
2008	31.863442389758177
2009	34.446227929374
2010	34.32044887780549
2011	31.557846506300113
2012	30.26463963963964
2013	32.840489053170316
2014	32.209639188833286