One approach ..
Assuming the source offload #s are in A2 down, with corresponding "reason"
in B2 down (A1:B1 are col headers)
First, sort both cols A and B by col A, descending.
Then place in C2:
=IF(B2="","",IF(COUNTIF($B$2:B2,B2)>1,"",ROW()))
(Leave C1 blank)
Put in D2:
=IF(ROW(A1)>COUNT(C:C),"",INDEX(B:B,SMALL(C:C,ROW(A1))))
Put in E2: =IF(D2="","",COUNTIF(B:B,D2))
Select C2:E2, copy down to last row of source data. Col D returns the unique
list of reasons sorted in descending order by the offload nos, while col E
yields the corresponding count of the reasons. D2

11 gives you the top 10
reasons by the offload nos. If you want the top 10 reasons by their counts,
copy cols D and E & paste special as values elsewhere, then do a sort on both
cols by the counts col in descending order & pick off the first 10 reasons in
the reasons col.