def percentage_step(self):
        """Return the step size for percentage."""
        if self._miot_property.value_range:
            stp = self._miot_property.range_step()
            return round(stp / self._miot_property.range_max() * 100, 2)
        return super().percentage_step
Return the step size for percentage.
custom_components/xiaomi_miot/fan.py