I have a range of #s and I want to count the first occurrence of each number.
I used CountIf but I received false results. See the example below. The
results for 300 should have been 3 for each occurrence. But I would prefer
to have 3 for the first occurrence of 300 and 0 for the 2nd and 3rd
occurrence. Help.

Column A Results
10 1
15 1
300 3
300 2
300 1
20 2
20 1