Jorge asked "does it make any sense to add those nine series to a single chart?“
My attempt to fix the chart by using some color coding, has its shortcomings that caused quite some discussion.
So again, how can you give the users all the data they expect while keeping the chart clean and readable?
D Kelly O’Day pointed out "More data or better colors won’t help a poor chart type selection" and presented a dot plot
Lets try to select the right chart type. In Chart Rules, As Simple as Possible, But Not Any Simpler! I presented an easy to learn set of rules to determine the best chart type .
1. Determine the relationship you want to display –
In our case a we have a Distribution Relationship, we want to show the Distribution of the Income Levels
2. Determine if you want to emphasize individual values or the overall pattern and
emphasize individual values or the overall pattern and Determine the chart type
As we want to emphasize individual values a column chart works best.
This chart already gives us a good feel for the income distribution in 1967- Looks like a almost perfect bell distribution with a belly for the mid income levels. But how did things change from 1967 to 2005? Lets create a set of small multiples to show the situation in 1967, 2005 and the increase from 1967 to 2005.