make sure selected academic year gets populated correctly

app/controllers/analyze_controller.rb

@@ -13,9 +13,12 @@ class AnalyzeController < SqmApplicationController
     @available_academic_years = AcademicYear.order(:range).all
     @academic_year_params = params[:academic_years].split(',') if params[:academic_years]
     @selected_academic_years = []
-    @academic_year_params.each do |year|
-      @selected_academic_years << AcademicYear.find_by_range(year)
+    if @academic_year_params.present?
+      @academic_year_params.each do |year|
+        @selected_academic_years << AcademicYear.find_by_range(year)
+      end
+    else
+      @selected_academic_years = [@academic_year]
     end
-    @selected_academic_years = [@academic_year] if @selected_academic_years.empty?
   end
 end