According to the Energy Office, Switzerland's final energy consumption increased by 2.5% in 2013 to 896,000 TJ (21.4 Mtoe) compared to 2012. The main reason for the increase was the cold weather, which led to an increase in consumption of energy carriers for heating purposes: in comparison to 2012 consumption of extra-light heating oil rose by 5.4% and use of gas by 5.9%. Electricity consumption increased by 0.6%. Consumption of energy generated from industrial waste (+2.3%) and from coal (7.6%) rose too. Consumption of heavy types of heating oil fell by 41.2%, and that of petroleum coke by 23.4%. Overall vehicle fuel consumption remained unchanged when compared to 2012. The trend of substituting diesel for petrol as vehicle fuel continued unabated: sales of diesel rose by 4.4% while petrol consumption fell again (-4.5%), a trend that has been observed every year since 2001. Positive developments in the economy also contributed to greater demand as did the continuing growth in the population.