Year % of total energy use 1990 0 1991 0 1992 0.0006358513369127288 1993 0.0007875812822503731 1994 0.008379296414542563 1995 0.028474446132989537 1996 0.01760900417338076 1997 0.019660591757213117 1998 0.026854621449906226 1999 0.04089174882651781 2000 0.029916275967951076 2001 0.03236504444850374 2002 0.024902298751771447 2003 0.03419617610059994 2004 0.04207594196057792 2005 0.11485216744511653 2006 0.146564186886771 2007 0.1290488549355342 2008 0.20272760908332244 2009 0.3394576205890525 2010 0.2965890252129447 2011 0.34911915342876954 2012 0.46162704479949634 2013 0.47377006000523836 2014 0.617871228736628 2015 0.9332367632531415