重新排列mutidimention数组PHP

I have an array $session that I extract from an awstats file:

# Session range - Number of visits
BEGIN_SESSION 7
1h+ 10
5mn-15mn 9
0s-30s 107
2mn-5mn 7
30s-2mn 21
15mn-30mn 4
30mn-1h 11
END_SESSION

First I wanted to rearrange this by adding the two values of 0s-30s & 30s-2mn and creating another one, here's how I tried it:

$newline="
";
$lines = explode($newline,$session);
$results = array();
foreach($lines as $line) {
     $parts = explode(" ",trim($line),2);
     if( count($parts) < 2) continue;
     else {
        $results[$parts[0]] = intval($parts[1]);
     }
}

$temp['0s-30s'] = (isset($results['0s-30s'])?$results['0s-30s']:NULL);
$temp['30s-2mn'] = (isset($results['30s-2mn'])?$results['30s-2mn']:NULL);
$results['0s-2mn'] = $temp['0s-30s'] + $temp['30s-2mn'];
unset($results['0s-30s'],$results['30s-2mn']);
$session = $results['BEGIN_SESSION'].$newline;
foreach($results as $k=>$v) $session .= $k." ".$v.$newline;
$session .= "END_SESSION";


$session = explode("
", $session) ; 
unset($session[(count($session)-1)]) ; 
unset($session[0]) ; 
unset($session[1]) ;
$sessions = array();

foreach ($session as $key => $value) {
    $session[$key] = explode(" ", $value) ;
    $sessions[] = array($session[$key][0],trim($session[$key][1])) ; 
}

and it displays me this array :

        Array
(
    [0] => Array
        (
            [0] => 1h+
            [1] => 10
        )

    [1] => Array
        (
            [0] => 5mn-15mn
            [1] => 9
        )

    [2] => Array
        (
            [0] => 2mn-5mn
            [1] => 7
        )

    [3] => Array
        (
            [0] => 15mn-30mn
            [1] => 4
        )

    [4] => Array
        (
            [0] => 30mn-1h
            [1] => 11
        )

    [5] => Array
        (
            [0] => 0s-2mn
            [1] => 128
        )

)

Is there a way to rearrange my array like this:

Array
(
    [0] => Array
        (
            [0] => 1h+
            [1] => 10
        )

    [1] => Array
        (
            [0] => 30mn-1h
            [1] => 11
        )

    [2] => Array
        (
            [0] => 15mn-30mn
            [1] => 4
        )

    [3] => Array
        (
            [0] => 5mn-15mn
            [1] => 9
        )

    [4] => Array
        (
            [0] => 2mn-5mn
            [1] => 7
        )

    [5] => Array
        (
            [0] => 0s-2mn
            [1] => 128
        )

)

Knowing that $session sometimes come with missing sessions. Any help with this? Thanks.

<?php

$session = 'BEGIN_SESSION 7
1h+ 10
5mn-15mn 9
0s-30s 107
2mn-5mn 7
30s-2mn 21
15mn-30mn 4
30mn-1h 11
END_SESSION';

$newline="
";
$lines = explode($newline,$session);
$results = array();

foreach($lines as $line) {
    $parts = explode(" ", trim($line), 2);
    if (in_array($parts[0], array('BEGIN_SESSION', 'END_SESSION'))) continue;
    else $results[$parts[0]] = intval($parts[1]);
}

$temp['0s-30s'] = isset($results['0s-30s']) ? $results['0s-30s'] : 0;
$temp['30s-2mn'] = isset($results['30s-2mn']) ? $results['30s-2mn'] : 0;
$results['0s-2mn'] = $temp['0s-30s'] + $temp['30s-2mn'];
unset($results['0s-30s'], $results['30s-2mn']);

$order = array('0s-2mn', '2mn-5mn', '5mn-15mn', '15mn-30mn', '30mn-1h', '1h+');

uksort($results, function($a, $b) use ($order) {
    return array_search($a, $order) < array_search($b, $order);
});

var_dump($results);