To do it yourself you can take the flexlm debug log file and process that to produce data that you can graph directly or write to a file for the likes of MS Excel to read and process. Note that this file is meant as a debug and may not be complete but I've observed that it does a pretty good job at recording things.
A tip if you are doing this is to make sure that when the licensing service is started that the log file is not overwritten but appended to, you do this by placing a "+" in front of the log file name in the settings. You can use the lmtools GUI interface on windows servers to configure the licensing with the "+" like:
Just remember to then replace/empty the file at some point, how fast it grows will depend on usage though I've never seen it being stupendously large even for a couple of years worth of data.
