In 2016, UK households were spending on average 4.0% of their total expenditure on energy, up from approximately 3% in the early 2000s. In 2016, households in the lowest income decile spent nearly 8.5% of their total expenditure on energy, this is down from the 10.6% observed in 2013 but well above 5.5% in 2004.
In 2015 the ONS changed how it reported data, from reporting the calendar year to the financial year. It reported both figures for 2014. From 2015-16 the chart reflects financial years rather than calendar years.
Energy is an essential service required for health and wellbeing. Consuming below the level of accepted thermal comfort may have serious health consequences, while worrying about how to meet fuel bills can also have psychological effects.