Test

[PGStats]

Please explain the value "1_0" in the second observation in more detail.

[PGStats]

OK, and what is the zero?

[PeterClemmensen]

I still don’t follow. Please explain further.

[PeterClemmensen]

Try this

data have;
input ID $ Number;
datalines;
A 1  
A 2  
A 5  
A 19 
A 19 
B 1  
B 3  
;

data want;
   set have;
   by ID;
   if dif(Number) not in (0, 1) then numberoftimes + 1;
   if first.ID then numberoftimes = 0;
run;

Result:

ID  Number  numberoftimes 
A   1       0 
A   2       0 
A   5       1 
A   19      2 
A   19      2 
B   1       0 
B   3       1