Year	% of total energy
1981	48.90241220225082
1982	48.253778023872904
1983	49.427008912638115
1984	50.075408673285935
1985	49.04887484461587
1986	46.32108052150818
1987	45.35671127446327
1988	44.636069496179886
1989	42.87296603686534
1990	34.53143045228037
1991	36.42959724955634
1992	33.803152783634786
1993	34.98087432837028
1994	36.202991318426044
1995	34.92755956325005
1996	35.583680169739154
1997	34.58499797846441
1998	30.045335610278784
1999	31.416221787314857
2000	28.536544201893925
2001	29.871666409742563
2002	28.806535516246925
2003	28.318036960329117
2004	25.195430211868576
2005	24.41479617724165
2006	24.02998414628962
2007	23.66835083382327
2008	22.805842459509925
2009	24.933985449356317
2010	23.24529086792144
2011	24.691582353600687
2012	22.21948562012658
2013	21.44283756684896
2014	19.97759640246668