How can I count the number of unique cells?

Question

I have a column in my spreadsheet that looks like this:
Date
Items
3/25
Item A
3/27
Item A
3/29
Item A
3/25
Item A
4/25
Item B
6/1
Item B
7/13
Item B
8/9
Item B
3/5
Item C
1/2
Item C
5/15
Item D
3/25
Item D
What I want is something that will list all the unique items that I have and count the number of times that Item shows up in my spreadsheet.  For example, the results should look like this:
Item A: 3
Item B: 4
Item C: 2
Item D: 2
I thought for sure that I can do a chart in numbers and it would count the number of items but no, not so much.

Answer 1

I apologize. When I pasted the table in Numbers running in French the values of column B were treated as dates.
I leave the screenshot untouched because the contents of this column changes nothing to the calculations.
In cell D2 of the main table, the formula is :
=IF(ISBLANK(C),0,IF(COUNTIF($C$2:$C2,"="&$C2)=1,COUNTIF(C,"="&$C2)+(ROWS(A)-ROW( ))/100000,0))
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In cell A2 of table aux, the formula is :
=IFERROR(LARGE(main :: D,ROW()-1),"")
In cell B2 of table aux, the formula is :
=IF(A>0,LOOKUP(A2,main :: D,main :: C),"")
In cell C2 of table aux, the formula is :
=INT(A)
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Yvan KOENIG (VALLAURIS, France) samedi 6 août 2011 23:33:10
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