对从文本文件中读取的升序数据进行排序

我有一个工作数据解析php脚本，它返回与它们相关的电影标题和评级。

<?php
header("content-type: text/plain");
foreach (glob("*.mov") as $filename)
$theData = file_get_contents($filename) or die("Unable to retrieve file data");
$months = ['January' => '_01', 'February' =>  '_02', 'March' => '_03', 'April' => '_04', 'May' => '_05', 'June' => '_06', 'July' => '_07', 'August' => '_08', 'September' => '_09', 'October' => '_10', 'November' => '_11', 'December' => '_12'];
foreach($months as $key => $month){
  if(strpos($filename,$month)!==false){
        echo "Movie List for $key 2013'n'n";
    }
}
$string = $theData;
$titles = explode("'n", $string);
function getInfo($string){
    $Ratings = ['G', 'PG', 'PG-13', 'R', 'NR', 'XXX'];
    $split = preg_split("/'"(.+)'"/", $string, -1, PREG_SPLIT_DELIM_CAPTURE); 
    if(count($split) == 3){ 
        preg_match("/(".implode("|", $Ratings).")'s/", $split[0], $matches);
        $rating = $matches[0];
        return ["title" => $split[1], "rating" => $rating];
    }
    return false;
}
foreach($titles as $title){
    $info = getInfo($title);
    if($info !== false){
        echo "{$info["title"]} : {$info["rating"]}'n";
    }
} 

输出如下:

Movie List for May 2013
(HD) Identity Thief : PG-13 
(HD) Escape from Planet Earth : PG 
(HD) Dark Skies : PG-13 
(HD) The Guilt Trip : PG-13 
(HD) Jack Reacher : PG-13 
(HD) Les Miserables : PG-13 
(HD) Mama : PG-13 
(HD) Safe Haven : PG-13 
(HD) A Place at the Table : PG 
(HD) Cirque du Soleil: Worlds Away : PG 
(HD) Rise of the Guardians : PG 
(HD) Fun Size : PG-13 
(HD) Shanghai Calling : PG-13 
(HD) The Package : NR 
(HD) The House at the End of the Street : PG-13 
Beautiful Creatures : PG-13 
The Incredible Burt Wonderstone : PG-13 
Jack the Giant Slayer : PG-13 
Parental Guidance : PG 
The Hobbit: An Unexpected Journey : PG-13 
Cloud Atlas : PG-13 
Life of Pi : PG 
Chasing Mavericks : PG 
Taken 2 : PG-13 
Adult title 1 : XXX 
Fat Burning Hip Hop Dance Party : G 
Fat Burning Hip Hop Dance Grooves : G 
Aladdin : G 
Americano : NR 
Missing Brendan : NR 
Point Doom : NR 
Gullivers Travels : G 
The Little Princess : PG 
Jack And The Beanstalk : PG 
To the Arctic : G 
Adult title 2 : XXX 

问题是:我如何对数据进行排序，使评级为XXX的电影显示在底部?任何的帮助是感激的。