BEGIN { 
  count = 0; 
  lastlabelalt = 0;
}

$3 != "" { 
  if( ($1 - lastlabelalt > 200) && ($1 < 18000) ) {
    printf "set label %d \"%d @ %d\" at %g,%g\n", ++count, $5, $6, ($6 < 15 ? $6+2 : 2), $1 ;
    lastlabelalt = $1;
  }
}