public function getStatistics()
    {
        $query_timer = 0.0;
        $slow_queries = array();

        foreach (self::$_log as $key => $val) {
            $query_timer += $val['execution_time'];
            if ($val['execution_time'] > 0.0999) {
                $slow_queries[] = $val;
            }
        }

        return array(
            'queries' => self::queryCount(),
            'slow-queries' => $slow_queries,
            'total-query-time' => number_format($query_timer, 4, '.', '')
        );
    }