$re = '/^(?:(?:\d+|\d{1,3}(?:,\d{3})*)\R){2,}/m';
$str = 'Peie
71,176,953
T-re
71,173,557
5-Mts
41,653,495
45678
Sia
36,136,829
36,100,829
4-Diepi
120,829
uteCra
36,100
Oct2018
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php