Year	% of energy use
1995	18.02461345385066
1996	17.922648112514032
1997	18.417237409413346
1998	18.412993472088477
1999	19.513027658129396
2000	20.33631777111964
2001	21.641885466366816
2002	18.636542521019166
2003	19.574299105621794
2004	24.478507569344725
2005	27.362104176798635
2006	29.684071417594758
2007	33.429593504911054
2008	34.69567871951019
2009	29.092641860635393
2010	31.66749634570103
2011	31.57697646291672
2012	31.932909284183342
2013	31.637960448714026
2014	33.116297507867905