Display Facebook share count

function facebook_share_count($url) {
 	$json_url = 'https://graph.facebook.com/' . esc_url(get_permalink());
	$json = file_get_contents($json_url);
	$json_output = json_decode($json);

	if(isset($json_output->shares)){
		$shares = $json_output->shares;
	}

}

But this doesn’t work.

var_dump($json_output);

get me this: object(stdClass)#2343 (1) { ["error"]=> object(stdClass)#2344 (4) { ["message"]=> string(38) "(#4) Application request limit reached" ["type"]=> string(14) "OAuthException" ["is_transient"]=> bool(true) ["code"]=> int(4) } }

How can I display share count without any plugin?