The charts show the percentage of three types of electrical appliances: , and from 1920 to 2019. The while the number of hours of decreased gradually over the time period.
The a washing machine was the highest 40% in 1920. to reach The a refrigerator but the percentage to 90% in 1960. There was a in 1980 and, after that, the rate was stable until the end of the period.
The amount of time doing housework was 50 hours per week in 1920 and decreased steadily to 20 hours per week in 1960. Then, the amount of time
