I am building a site where users will fill webforms (these are quality of life questionnaires). Users will fill the same form several times. I want to show the change in the value of fields in the webform. For example, if there is a field, say score 1 which has a value of 10 on 13 May 2020, and 15 on 14 May 2020, I want to show that the value has changed by 5 points.
I want to show this using Views as it will allow us to filter by dates on which the form was filled as well as the users (and use contextual / exposed filters).
The Views Aggregator field allows us to calculate the range for a column and using the a modified range formula (which the maintainer kindly developed very quickly) we can show the difference between two values. However, this is constrained to be displayed as a table row and not a field.It also has the disadvantage that the value is always maximum - minimum of the two values.
Is it possible that we can get this as a field in Views (so that I can apply custom css code). The motivation for doing this is to show the value in different colors depending on the value (e.g. red color if the value is more than 10 and green if it is less than 5).
It is noteworthy that each questionnaire can have many different scores computed and I would like to make a display for each. Note that for the display of the change we are looking for change of the recent value as compared to last filled.
Any pointers will be appreciated. 
