A glance at these two line graphs provided reveals some striking correlations between the percentage of electrical appliances owned by each family and the length of time spent on weekly housework by each household during the period from 1920 to 2019. It is evident that the amount of houseworks’ time decreased significantly as the ownership of electrical appliances rose correspondingly.

In the first graph, all electrical appliances rose during the first 40 years from 1920 to 1960. More specifically, between 1920 and 1960, washing machine increased slightly from 40% to 70%, while vacuum cleaner went up from 30% to 70% and catch up with washing machine at 1960. Amazingly, during this period, refrigerators got an explosive growth from under 5% to 90%, which surpass vacuum cleaner around 1938 and washing machine around 1945. Over the next 59 years, there were some small changes in things. Although washing machine slight declined between 1960 and 1980, it still went up from 65% to 75% during the next 39 years. Meanwhile, refrigerator and vacuum cleaner respectively peaked at 100% in 1980 and 2000 and remained stable in the remaining decades.

It is interesting to note that while the electrical appliances jumped quickly between 1920 and 1960, the housework time shrank dramatically by 60% from 50 hours a week in 1920 to 20 hours a week in 1960. After this, as growth of electrical appliances gradually slowed, the housework time remained the downward trend and gradually went down around 10 hours a week in 2019.