average on a stacked bar chart

Hello, 

I'm trying to figure out how to add an average metric to each question in my stacked bar chart. The first graph is displaying survey results and giving the total count for each response. The second graph, I converted the responses to a point scale so it's summing the the points for each response (1=Strongly Disagree, 2 = Disagree, 3 = Neutral, 4=Agree, 5=Strongly Agree). I thought I could use the second graph to generate an average score for each question but I wasn't sure how to do that. Any suggestions?