remove Max values in an index column

Let's say your last step was PriorStep. I would group by Shipment # column, and choose the Max Aggregation for the ORDER COUNT column. Name that step "Group" or whatever you want. Then you can join that table to PriorStep using a left anti join. So after grouping, 

= Table.Join(PriorStep, {"SHIPMENT #", "ORDER COUNT"}, Group, {"GROUPED SHIPMENT # COLUMN", "Max ORDER COUNT"}, JoinKind.LeftAnti)

Side note: using the "#" character in your column name is going to get you into trouble some day, because somehow it'll get parsed as an escape character and mess up your quotes.

--Nate