Well, you need to go to PBEC tab on the bottom. Select RIR or TR (whichever is your wife's type) - "RIR Philly" or "TR Philly". There in the top right corner you'll see estimated time to finish the backlog - "Time to finish". It is estimated based on how many cases BEC processes each week and how many cases are remaining. This is "worst case scenario" if your case is approved among the last.
You can see at the graphs to see weekly progress and percantage of cases in different status.
If you want to look at your particular "lot" or your day - go to "Most active Philly" tab. There you can find your day (that would be 05166) either on the graph or in the first column and see the number of cases entered on that day (second column), number of cases processed from this "lot" on previous week (third column), and total number of cases processed from this lot (third column). You can see those things on the graphs as well - the tallest graph is the total number of cases, second line is number processed to date and the dots - number of cases processed last week.
The vertical axis is logarithmical, so it amplifies number of cases processed last week (otherwise you wouldn't see them, they would all be at the bottom).
This would give you some idea of the pace the BECs are processing cases and when to expect the certification. As you'll see, looks like RIR cases will be certified pretty soon, there are not many left and they are being processed with good speed and the speed is increasing.
Hope this helps you and others, who don't understand the numbers and graphs in the Excel.