Question

which heading should replace the question mark in the chart below?

year	?
1918	1.4
1919	1.4
1920	5.2
1921	11.7

unemployment rate in percent
immigration from asia in millions
immigration from europe in millions
women in the workforce in percent

Explanation:

The values in the chart are numerical data over years. Unemployment rate is a common data - point tracked over time and the values seem to be percentages which is typical for unemployment rates. Immigration data in millions would be whole numbers or larger values in most cases for the time period given, and women in the workforce percentage might not have such a rapid increase in such a short time - span as shown.

Answer:

Unemployment Rate in Percent