$re = '/(?<=[( ])\d{4}(?=\S*\)|$)/m';
$str = 'Grumpier Old Men (1995)
Death Note: Desu nôto (2006–2007)
Irwin & Fran 2013
9500 Liberty (2009)
Captive Women (1000 Years from Now) (3000 A.D.) (1952)
The Garden of Afflictions 2017
The Naked Truth (1957) (Your Past Is Showing) ';
preg_match_all($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