How to parse more than 200 xml files?

Question

PHP

It is necessary to parse more than 30 xml files. Using the code below does not work, the error "failed to open stream: HTTP request failed!"
Here is the code:

for($i=16000000; $i <= 16000250; $i++) {
        $xml = simplexml_load_file("http://site/?id=$i");
        if($xml->error == "0") {
            echo $xml->people. "<br>";
        }
    }

Answer 1

sleep(5) at least....
and isn't it easier with curl?

Answer 2

use guzzle, exception handling, sleep and console script, not web.