Year kg per kg of oil equivalent energy use 1971 2.776353869850739 1972 2.5287160421530954 1973 2.7356003864811065 1974 2.9145972482079956 1975 2.80520918621235 1976 2.6980011808474673 1977 2.6992875064254895 1978 2.621392321527516 1979 2.9988114706889877 1980 2.9488766459694418 1981 2.9197494217992723 1982 3.0178362962605214 1983 3.0264044138417057 1984 2.937620028396208 1985 2.890779439533608 1986 2.9628512655610875 1987 3.0776082814640344 1988 3.086376885014601 1989 3.0759025723168434 1990 2.8522776152123925 1991 2.929031624673263 1992 2.9786499428325612 1993 2.952066753524243 1994 2.984648635342887 1995 3.127021989175792 1996 2.9437784175494435 1997 2.998181518390626 1998 3.0116015037251227 1999 2.9739814934422792 2000 3.021183953801387 2001 3.1607324029947512 2002 3.2233397084204127 2003 3.2324981711978746 2004 3.0070514893925315 2005 2.99713927805254 2006 3.059863827779019 2007 3.065681109816384 2008 3.104042071461259 2009 3.1039314663723974 2010 3.1415629480576586 2011 3.1399871357786076 2012 3.2226930741405857 2013 3.1861168107674955 2014 3.2220902630971566