Housing conditions and energy efficiency Households according to whether they have made improvements to thermal insulation or the heating system, by income quintile per unit of consumption. Unidades: Horizontal percentages. ,Has made improvements to thermal insulation or the heating system,No improvements have been made and it is warm enough during the cold months,No improvements have been made and it is not warm enough during the cold months, Total,14,1,60,8,25,1, First quintile,9,54,6,36,4, Second quintile,12,56,6,31,4, Third quintile,13,5,60,9,25,6, Fourth quintile,16,64,2,19,8, Fifth quintile,19,9,67,3,12,8, Notas: Income per unit of consumption is obtained, for each household, by dividing total household income by the number of units of consumption. The distribution of persons is taken. Fuente: Instituto Nacional de Estadística