def value(self) -> float:
    if ((self._value == 0) or (self._end == self._start)):
        return 0
    return (self._value / (self._end - self._start))
def value(self) -> float:
    if ((self._value == 0) or (self._end == self._start)):
        return 0
    return (self._value / (self._end - self._start))