code: def deductible(self, loss_type, dummy=None):
          
          val = self.calc(loss_type, self.deductibles, self.area, self.number)
          if self.calc.deduct_abs:  # convert to relative value
              return val / self.calc(loss_type, self.values,
                                     self.area, self.number)
          else:
              return val
docs: :returns: the deductible fraction of the asset cost for `loss_type`