[Admin]

in index.php replace this:

$countthreads=$DB_site->query_first('SELECT COUNT(*) AS threads FROM thread');
$totalthreads=number_format($countthreads['threads']);

With this:

$countthreads=$DB_site->query_first('SELECT COUNT(*) AS threads, SUM(views) AS views FROM thread');
$totalthreads=number_format($countthreads['threads']);
$totalviews=number_format($countthreads['views']);

And use $totalviews.