Clearing Interface Data

So all of my interface throughput graphs have gone weird. They are showing interface speeds of 400TBps......which unless I somehow traveled to the future, doesn't exist.

Now I've encountered this problem in previous versions of Zenoss and it seems to be caused because the graphs graph the difference not the absolute value, so sometimes when a device first gets added it thinks it does that speed and then from there on in it graphs the difference off the initial value.

Before in v3 or v4 I could just go in and clear out the RRD files and it fixes it because it resets the inital value, but in v5 there is no RRD files.....

TLDR; How would I go about clearing out interface data from v5