data s;
  filename s 'stvin.dat';
  infile s;
  length constit $ 30;
  input year constit & regelec ncast naccept nreject vind vind1
    vplm vppp vsvlp;
  ncands=5;
  if vind=0 then ncands=ncands-1;
  if vind1=0 then ncands=ncands-1;
  if vplm=0 then ncands=ncands-1;
run;