Time in Status report screen shows charts for individual report rows and an overall chart for aggreagated reports.
Look for this button on the page to see where charts are available: 
Chart Types
There are several chart types that you can select using the chart-type button on the top-left corner.
Percentages
If you want to see percentage calculations in the charts, Time in Status offers multiple options for this.
The Percentages button is located at the top of the chart window.
In the default setting, the chart does not show any percentage calculations.
If you choose the 'Show percentage of overall chart' option, each individual value is shown as its percentage with respect to the whole chart.
If you choose the 'Show percentage of stack/cluster' option, each individual value is shown as its percentage with respect to the stack/cluster to which it belongs.
Exclude Current State
If you are looking at an issue that hasn't been updated for a long time (for example the issue was closed months ago), the charts will be completely dominated by the latest state of the issue and earlier statuses/assignees will not be distinguishable in the chart.
To overcome this you can use the Exclude Current State checkbox. When checked, this option causes the status/assignee duration since the last change in issue history to be excluded from the report. This way charts display much more useful output.
Please note that Exclude Current State does not exclude the latest status completely but rather excludes the duration since the latest status/assignee change in issue history. If the issue has visited Closed status more than once, the Closed column will still display a value grater than zero when Exclude Current State is checked.
If you want to exclude a status completely, you can uses the Statuses selection to select individual statuses to be included in the report.