We have added a new column for Percentage (By Duration) in JMC 8.1.0. There were few suggestions after that enhancement which we are incorporating as part of this follow up Enhancement.

JMC-7041 has introduced a  Percentage (By Duration) column in that stack trace view, that shows time spent on stack frames for selected events.  

  It would make more sense if the Percentage (By Duration)is mapped with the actual Duration just as in Count. For example

The total count of selected events is  60 in the above image,  which is an aggregate of  30 Short, 20 Medium, 10 Long events. The event distribution within stack-trace is represented as follows.

•  30 ShortSleep events (50% of 60 Total)
•  20 MediumSleep events (33.3% of 60) 
•  10 LongSleep events 16.7% of 60)  

Similarly, an aggregation of Duration (with the time unit) can also be shown as a column next to Count, and the table columns could be      Count, Duration,  Count %, Duration %

 The tooltip for Percentage (By Duration), is trying to give the aggregate duration, but it's difficult to grasp in its current form.   It could be 1.19 TimeUnit of 5.39 TimeUnit (22.2%) spent in the stack trace

Format tooltip to show timestamps in a better way.

The Show Percentage by Duration is shown as NaN%  in Method Profiling and Exception JFR Pages.