Using most recent data for chart

I am trying to make a chart that shows the amount of overdue projects vs on time projects. This file gets new information added to it every week. This means if something was overdue last week and still overdue this week it will count it on the graph twice. Is there a way that if there any duplicates of an item it can only count it as one? I cant simply delete the old one either because there are other graphs that show overdue by week and what not. Any help would be appreciated.
Thanks.

Post an example sheet by going "Go Advanced" and attaching it.

might provide a better way for others to see the data.

Cheers

Okay so attached is a sample file (some data missing because its sensitive material.) Anyways I need to make a pivot chart that shows the on-time items (green) and overdue items(red). Basically this file is updated every week with new information. If a file is done it does not show up on the next week export file (which gets imported into the bottom of this file). So some of these files are shown up multiple times and as the time passes they go from on-time to overdue. I want my graph to only show the most recent of the duplicate items. So if you look in the attachment row 6(change number=99017 & workitems=26010 (the combination of the 2 make the item unique)) starts off on time, but as the weeks pass (row 15) the item becomes overdue. I don't want the graph to show both of the days before deadline on the graph because it will show one as over due and one as on-time. i just want to show the newest one. I tried to make this as clear as possible but it might still be confusing. Let me know if there are anymore questions.

updated attachment

Hi, I assume that if end date is earlier then the export date ten it is Overdue anyway, and if the job is done then there would be a date in the done column.

If so then this formula in Q2 will lock the days before deadline at the day that the job was done.
=IF(O2="",N2-P2,N2-O2)

But if you didn't actually need anything in column Q once the job is done...then in Q2 try:
=IF(O15="",N15-P15,"")
and change the green conditional formatting to =$R$2="OnTime"

Edit:- Just realised that doesn't solve the initial issue of having multiple entries which will skew the data. Sorry.