Year % of total final energy consumption 1990 1.7 1991 1.7 1992 2 1993 2 1994 2.8 1995 4 1996 3.1 1997 4.4 1998 6.7 1999 5.9 2000 6.8 2001 3.4 2002 1.3 2003 1.3 2004 1.4 2005 1.9 2006 2.1 2007 3.6 2008 4 2009 3.7 2010 3.7 2011 3.8 2012 4.2 2013 5.7 2014 6.8 2015 9.1 2016 13.5 2017 15.3 2018 16 2019 16.4 2020 20.8 2021 20.5