I have a table of data with 2 columns.

Column 1 contains order numbers.

Column 2 contains a time stamp (the hour in which the order number occurred).

I want to make a count of the number of distinct orders that happened in each hour.

Normally a Countif would work, however the data has been produced in such a way that if an order has three items in it, there are three occurrences of the Order number.

Column A ____ Column B

1001 _________ 9

1001 _________ 9

1001 _________ 9

1002 _________ 9

1003 _________ 10

1004 _________ 11

1004 _________ 11

1004 _________ 11

1005 _________ 11

The result I would be looking for is:

Time _____ Count of Order Numbers

9 _________ 2

10 _________ 1

11 _________ 2

Any help would be hugely appreciated.