Year	% of output
1971	14.000000000000002
1972	13.965980304386749
1973	14.012738853503185
1974	14.982078853046596
1975	15.724815724815725
1976	13.756045137023106
1977	15.339098771051434
1978	15.12476007677543
1979	16.742969260954872
1980	14.798339264531435
1981	14.514378730330982
1982	17.975356366272045
1983	18.103648617243785
1984	19.7310405643739
1985	20.930232558139537
1986	22.505985634477256
1987	20.078008915304608
1988	21.857826626484666
1989	22.776911076443056
1990	22.5389825169318
1991	23.573272153713795
1992	22.192884936075597
1993	23.478612872756713
1994	24.32465618860511
1995	24.961442638509908
1996	23.297644539614563
1997	24.483690407257285
1998	23.094582185491277
1999	23.612727978269305
2000	24.133056916698077
2001	24.597285067873305
2002	24.35228802153432
2003	26.23419366014204
2004	25.477707006369428
2005	26.800788954635106
2006	24.99467140319716
2007	21.823845590031762
2008	19.22729446776851
2009	18.003123485378858
2010	16.86401148188016
2011	16.301596573208723
2012	14.496432792051472
2013	12.953011478440308
2014	12.922203480478874