If there are two series to be represented against one parameter in the chart where one series value is always going to be high compared to the other, better representation would be to show the two series on different sides of Y-Axis.
The below table shows the number of professionals passed/failed in the certification exams on a particular date, where most of the time the Fail ratio is lower than the Pass ratio.
Following are the steps on how you would represent both series values on different sides of Y-Axis using DUNDAS Charts:
a. Add both Pass & Fail series as values & group it by date as in the following chart.
b. Double-click on 'Failed' series, for its details. Go to 'Series' Tab.
c. Select the Y-Axis Type value from the drop-down as 'Secondary'.
d. Below is how it would look like.