my @stop_list;
my @distance;
while($sth -> fetch()){
    if((not defined($distance[$service]) or
       $distance[$service] > $distance) {

         $stop_list[$service] = $stops;
         $distance[$service] = $distance;
     }
}
foreach $service (@stop_list) {
   print "Stop: $stop_list[$service] distance: $distance[$service]\n"
}