The line graphs show changes in (1) the proportion of the population in a specific country that owned three types of domestic electrical appliances, and (2) the number of hours spent on housework (meal preparation, laundry, and cleaning) weekly, from 1920 to 2019.
Overall, it is clear that the popularity of these domestic appliances surged, particularly refrigerators and vacuum cleaners. Also, the total time spent on housework decreased dramatically over the same period.
The most significant change, initially, was in the ownership of refrigerators. Ownership rose from 0% in 1920 to more than 50% by 1950 before leveling off at 100% around 1980. The popularity of vacuum cleaners increased steadily from 1920 until 2000, by which time every home had one. In contrast, the number of people that owned a washing machine rose gradually from 1920 onwards, but almost 25% of homes were still without one in 2019.
The most significant reduction (from 50 to 20) in the number of hours spent on housework occurred between 1920 and 1960, reflecting the rapid rise in ownership of domestic appliances over the same period. From 1960 onward, there was a significantly smaller but steady reduction in the hours spent on the three housework tasks mentioned.