Would you be able to explain in more detail what you're looking for? It may be that we already provide what you need by default.
The Sum and Average chart only looks at data that was filled in for the field when doing its calculations. The footer on the chart reports what percentage of total submissions had an answer filled in for the field.
The Bar chart also reports only on submissions with an answer filled in for the field, with a footer showing what percentage of total submissions had an answer filled in for the field.
The Count chart tells you how many responses included an answer for the field.
The Likert chart reports only on filled in data (ignoring unanswered questions), with the Total Responses column showing how many submissions had something filled in for each question - reported as a number and a percentage of total submissions.