Create new variable equal to number of occurrences of var1

* To add a variable which contains the number of occurences of the value of var1.
* Thus with the following data, we want 
n=2 for cases where var1=25 and 
n=3 for cases where var1=10.

DATA LIST LIST /var1(F8).
BEGIN DATA.
25 
10 
10 
25 
10
END DATA.
LIST.

SORT CASES BY var1.
SAVE OUTFILE='c:\\temp\\temp.sav'.

AGGREGATE
  /OUTFILE=*
  /BREAK=var1
  /N_BREAK=N.

MATCH FILES /TABLE=*
 /FILE='c:\\temp\\temp.sav'
 /BY var1.
EXECUTE.