;1st quarter 2018;Change in per cent;Change in per cent;4th quarter 2017;1st quarter 2017;Breakdown of electricity sales by volume. Per cent; Last 3 mos.;Last 12 mos.; HOUSEHOLDS;42.5;18.1;23.9;36.0;34.3;100.0; New fixed-price contracts, 1-year or less, households;32.9;7.5;2.8;30.6;32.0;0.4; New fixed-price contracts, more than 1-year, households;27.6;-19.5;-6.8;34.3;29.6;0.2; Older fixed-price contracts, households;30.4;-0.7;0.7;30.6;30.2;1.5; Contracts tied to spot price, households;42.2;20.9;31.5;34.9;32.1;72.3; Variable price contracts, households;44.4;13.8;12.1;39.0;39.6;25.6; SERVICES;39.0;18.9;26.2;32.8;30.9;100.0; New fixed-price contracts, services;28.7;-0.7;2.1;28.9;28.1;4.4; Older fixed-price contracts, services;32.1;11.5;8.8;28.8;29.5;2.8; Contracts tied to spot price, services;39.5;20.4;28.7;32.8;30.7;86.1; Variable price contracts, services;42.2;15.9;19.9;36.4;35.2;6.8; MANUFACTURING EXCL. ENERGY-INTENSIVE MANUFACTURING;38.6;18.8;29.1;32.5;29.9;100.0; New fixed-price contracts, manufacturing excl. energy-intensive manufacturing;30.6;0.0;5.9;30.6;28.9;0.8; Older fixed-price contracts, manufacturing excl. energy-intensive manufacturing;29.3;-1.0;0.0;29.6;29.3;4.2; Contracts tied to spot price, manufacturing excl. energy-intensive manufacturing;39.0;19.6;31.3;32.6;29.7;92.4; Variable price contracts, manufacturing excl. energy-intensive manufacturing;42.6;16.1;17.4;36.7;36.3;2.6; ENERGY-INTENSIVE MANUFACTURING;31.4;9.0;1.6;28.8;30.9;100.0; Fixed-price contracts and contracts not entered in the market, energy-intensive manufacturing;:;:;:;:;:;:; Contracts tied to spot price, energy-intensive manufacturing;36.7;23.6;22.7;29.7;29.9;:;