Final answer:
The provided information does not specify the increase in divorce rates for the 1920s. However, it does illustrate a significant rise in divorce rates from 1960 to 1980, followed by a decline to rates similar to those in 1970.
Step-by-step explanation:
The rate of divorce in the 1920s is not explicitly detailed in the provided information. However, the information does indicate that from 1960 to 1980, the United States experienced a significant rise in divorce rates, doubling from 9.1 per 1,000 married persons in 1960 to 20.3 by 1975 and peaking at 22.6 in 1980.
This increase has been attributed to the liberalization of divorce laws and societal changes, such as more women entering the workforce. Subsequently, the divorce rates have declined, aligning more with the rates of 1970. Factors contributing to this decline include an increase in the age of marriage, higher levels of education, and a decrease in marriage rates overall.