What Is The Use Of Stats Variable In Backend Index.php File

in below path ,

\app\controllers\backend\index.php

$timestamp_from = $time_period['from']->getTimestamp();
$timestamp_to = $time_period['to']->getTimestamp();

$time_difference = $timestamp_to - $timestamp_from;
$stats = base64_decode('PGltZyB......');

why we use $stats variable in cs cart application..?