diff --git a/app/controllers/report_controller.rb b/app/controllers/report_controller.rb
--- a/app/controllers/report_controller.rb
+++ b/app/controllers/report_controller.rb
@@ -52,6 +52,8 @@
     #set up range from param
     @since_id = params.fetch(:from_id, 0).to_i
     @until_id = params.fetch(:to_id, 0).to_i
+    @since_id = nil if @since_id == 0
+    @until_id = nil if @until_id == 0
 
     #calculate the routine
     @scorearray = calculate_max_score(@problems, @users, @since_id, @until_id)