how to add new rows in this case

[MC10]

Hi all, 

I have a coding problem. Basically, I want to add more rows and change Data A to Data B.

That is, for each code A and B, I want to have observations for 2004, 2005, ..., 2011. 

In Code=B, new rows before the first year in Data A should include the first year's value, while new rows after the last year in Data A should include the first year's value.

Could you help me how to make a code for the transformation from Data A to Data B?

Thank you!

(Data A)

Code              value                             year

A	10	2005
B	8	2005
B	8	2006
B	9	2007
B	10	2008
B	10	2009
B	11	2010

(Data B)

Code              value                             year

A	10	2004
A	10	2005
A	10	2006
A	10	2007
A	10	2008
A	10	2009
A	10	2010
A	10	2011
B	8	2004
B	8	2005
B	8	2006
B	9	2007
B	10	2008
B	10	2009
B	11	2010
B	11	2011

[Kurt_Bremser · Accepted solution]

Do this:

data want;
set have;
by code;
if first.code then do year = 2004 to year - 1;
  output;
end;
output;
if last.code then do year = year + 1 to 2011;
  output;
end;
run;

Untested; for tested code, supply example data in a data step with datalines.

[MC10]

It works perfectly! Thank you very much for the help.