I am trying to get a count of how many items in a spreadsheet I have an
example below. Basically if the number is listed more than once then it is a
part to an assembly and it only needs to be counted once so for the below
data it would return the number 8 because there are only 8 diffrent numbers.

PS-AA1-120
PS-AA1-120
PS-AA1-121
PS-AA1-121
PS-AA1-122
PS-AA1-122
PS-AA1-123
PS-AA1-123
PS-AA2-001
PS-AA2-001
PS-AA2-002
PS-AA2-002
PS-AA2-002
PS-AA2-003
PS-AA2-003
PS-AA2-004
PS-AA2-004
PS-AA2-004