SAS assignment week 2 - most recent year

SAS_assignment_week_2_most_recent_year.sas

data returns;
  input @01 id       
  	@03 date  MMDDYY10.
        @14 return;
format date date9.;
datalines;
1 10/31/2013 0.01
1 11/30/2013 0.02
1 12/31/2013 0.03
1 01/31/2014 -0.01
1 02/28/2014 0.01
2 10/31/2013 -0.01
2 11/30/2013 0.02
2 12/31/2013 0.01
2 01/31/2014 -0.02
2 02/28/2014 -0.03
2 03/31/2014 0.02 
run;

data yearly;
  input @01 id        
  	@03 date  MMDDYY10.
        @14 equity;
format date date9.;
datalines;
1 12/31/2011 8
1 12/31/2012 10
1 12/31/2013 11
2 12/31/2012 30
2 12/31/2013 28
run;