PHP将复选框值排列在两列中

我有一个带有复选框的表单，我想将复选框排列在两列中，而不是单个长列。

如何将其分割为两列?

if($proceder == True) {
        echo "<form name='formulario' method='POST' action='iconizar.php'>";
        $iconosm = 0;
        $server_groups = $ts3_VirtualServer->serverGroupList();
        $servergroups = array();
        # En vez de iterar por todos los grupos intenten 
        foreach($server_groups as $group) {
            if($group->type != 1) { continue; }
            if(in_array($group["sortid"], $SID_GROUP)) {
                $servergroups[] = array('name' => (string)$group, 'id' => $group->sgid, 'type' => $group->type);
            }
        } 
        $_SESSION['grupos'] = $servergroups;
        foreach($servergroups as $group) {      
            $miembros = $ts3_VirtualServer->serverGroupClientList($group["id"]);
            $estaengrupo = False;
            foreach($miembros as $m) {
                if($m["client_unique_identifier"] == $client_uid) { 
                    $estaengrupo = True; 
                }                                   
            }
            if($estaengrupo) {
                $iconosm = $iconosm + 1;
                echo '<li><img src="./iconos/icons/'.$group['id']. '.png" alt="" />  ';
                echo '<label><input type=checkbox name=grupos['.$group["id"].'] id="'.$group["id"].'" value="'. $group["id"] .'"class="icono" checked >'.$group["name"].'</label><br>';
            } else {
                echo '<li><img src="./iconos/icons/'. $group['id'] . '.png" alt="" />  ';
                echo '<label><input type=checkbox name=grupos['.$group["id"].'] id="'. $group["id"] .'" value="'. $group["id"] .'" class="icono"> '.$group["name"].'</label><br>';
            }           
        }