Dear Ken,
These numbers are computed base on your configuration, e.g. mode, plant type, soil type, sprinkler type, and are not open to public. Roughly speaking, the low/high are around 60%-90%, which is also a good starting point if you want to use customized mode. The flow rate is based on sprinkler type, a good estimation is :
mister: 2.0inch/hour
fixed spray head: 1.5inch/hour
bubbler: 1.0inch/hour
rotor head: 1.0inch/hour
rotary nozzle: 0.7inch/hour
rotary emiter: 0.5inch/hour