The overall response rate is artifically lower because we are including the number of all the students at the school, not just the number of students that took the survey. Updated the overall response rate presenter to return the count of only the grades that took the student survey.

app/presenters/response_rate_presenter.rb

@@ -14,6 +14,8 @@ class ResponseRatePresenter
   end
 
   def percentage
+    return 0 if respondents_count.zero?
+
     cap_at_100(actual_count.to_f / respondents_count.to_f * 100).round
   end
 
@@ -37,9 +39,30 @@ class ResponseRatePresenter
   end
 
   def respondents_count
-    respondents = Respondent.find_by(school:, academic_year:)
-    count = respondents.total_students if focus == :student
+    return 0 if respondents.nil?
+
+    count = enrollment if focus == :student
     count = respondents.total_teachers if focus == :teacher
     count
   end
+
+  def enrollment
+    SurveyItemResponse.where(school:, academic_year:, grade: grades,
+                             survey_item: SurveyItem.student_survey_items)
+                      .select(:grade)
+                      .distinct
+                      .pluck(:grade)
+                      .reject(&:nil?)
+                      .map do |grade|
+      respondents.counts_by_grade[grade]
+    end.sum.to_f
+  end
+
+  def respondents
+    Respondent.find_by(school:, academic_year:)
+  end
+
+  def grades
+    respondents.counts_by_grade.keys
+  end
 end