def get_numeric_score_increment(self):
if self.is_based_on_grades():<EOL><INDENT>raise errors.IllegalState('<STR_LIT>')<EOL><DEDENT>if self._my_map['<STR_LIT>'] is None:<EOL><INDENT>return None<EOL><DEDENT>else:<EOL><INDENT>return Decimal(str(self._my_map['<STR_LIT>']))<EOL><DEDENT>
Gets the incremental step.

        return: (decimal) - the increment
        raise:  IllegalState - ``is_based_on_grades()`` is ``true``
        *compliance: mandatory -- This method must be implemented.*