ams-esbj hourly traffic in percent of capacity week 39 in 2021

/data/traffic/plot/plot-hr -n ams-esbj -d 2021--39 -t traffic -f png  >/data/traffic/html/imgs/hr.traffic.ams-esbj.2021--39.png
Illegal division by zero at /data/traffic/plot/plot-hr line 97.
Plot failed, ret = 255