sthb-ore hourly traffic in percent of capacity 2020-07-04

/data/traffic/plot/plot-hr -n sthb-ore -d 2020-07-04 -t traffic -f png  >/data/traffic/html/imgs/hr.traffic.sthb-ore.2020-07-04.png
Illegal division by zero at /data/traffic/plot/plot-hr line 97.
Plot failed, ret = 255