DHC-4 Caribou reports a DESIGN_SPEED_MIN_ROTATION of -1.688

Design values:

DESIGN_CRUISE_ALT: 15000
​DESIGN_SPAWN_ALTITUDE_CRUISE: 1500
​DESIGN_SPAWN_ALTITUDE_DESCENT: 500
​DESIGN_SPEED_CLIMB: 177.24583799999982
​DESIGN_SPEED_MIN_ROTATION: -1.6880555999999982
​DESIGN_SPEED_VC: 297.0977855999997
​DESIGN_SPEED_VS0: 61.008881519896185
​DESIGN_SPEED_VS1: 70.01019190807759
​DESIGN_TAKEOFF_SPEED: 70

All of those make sense except for the minimum rotation speed, which is physically impossible.