Each graph displays either a single
response category, or a combination of categories, over time.
The horizontal axis identifies the range of years in which the question was asked, while the dot
markers on the trend line specify the exact years when the question was asked. The vertical axis
gives the percentage of respondents who chose the response category given at the top of the graph
(for tables containing averages or scores on indices, the averages or scores on the index are represented on the vertical axis). On the graph below, for example, the data displayed correspond
to the data that appeared in the initial table for the response category Few Big Interests. Other relevant information, such as the date the graph was produced, is given below the graph.