'return confidence based on existing data'

def get_confidence(self):

    if ((self._total_chars <= 0) or (self._freq_chars <= self.MINIMUM_DATA_THRESHOLD)):
        return self.SURE_NO
    if (self._total_chars != self._freq_chars):
        r = (self._freq_chars / ((self._total_chars - self._freq_chars) * self.typical_distribution_ratio))
        if (r < self.SURE_YES):
            return r
    return self.SURE_YES
