Timechart, last value is always 0

Hi, I have this query index=os sourcetype=vmstat OR sourcetype=cpu OR sourcetype=df host=betamax-admin Filesystem="/dev/mapper/vg_betamaxadmin-lv_root" | timechart span=5m max(PercentUsedSpace) All it does it gets the % of diskspace used for a given host. Yet when I run it, the most recent value is always 0, which is odd. (see attached pic) I wait a few minutes and try it again and the time changes but still the value is 0 ![alt text][1] [1]: /storage/temp/159239-timechart-most-recent-value-zero.png