In the frequency report there is a misunderstanding between the count of submissions and the count of answers to the item id=xxx. Of course they may be different and this is leading to sum of percentages different from 1.

Second problem is that the string in the first column of the report table is not correct because the value "SURVEYPRO_ANSWERNOTINDBVALUE" is not managed in the public method userform_db_to_export($answer, $format='') of each field class.