Item Contract Delivery Planned Delivery
a 2008-47 2008-48
b 2008-48 2008-48
c 2008-47 2008-47
b 2008-49 2008-50
a 2008-50 2008-50
b 2008-47 2008-50
c 2008-47 2008-47
b 2008-51 2008-51
a 2008-51 2008-51
a 2008-46 2008-49
c 2008-48 2008-48
b 2008-49 2008-51
a 2008-49 2008-49
c 2008-50 2008-50

Week Total Delayed per week
2008-46 Formula???
2008-47 Formula???
2008-48 Formula???
2008-49 Formula???
2008-50 Formula???
2008-51 Formula???

I've got this information. What formula can I use to display how many items
are delayed per week? I intend to use this information to make an overview
over delayed items and the progress on the backlog.

Hope anyone understand my question and can help me.