You can view your call volume separated by missed calls. To review these statistics, expand the "Call Analytics" category in the column on the left of your 800.com account and select "By Missed Calls" from the list. 

This will bring you to the analysis screen. You can change the date range by clicking on the date box on the upper right of the screen. All of your numbers will be selected and displayed by default. You can look your telephone numbers individually by clicking on the drop-down box that states "All Numbers" on the upper left. By default, "Calls By Day Of Week" will be displayed. You can view calls by hour of day by clicking on the next drop-down and selecting "Calls By Hour Of Day."

The graph on the left will show the answered calls in blue and missed calls in yellow, as well as display a total. If the call volume is too small to view relative to another number's you can hover over that portion of the graph and a bubble will appear displaying the information. The graph on the right will show what percentage of calls are missed and the number of calls missed relative to your total calls underneath.