Order By Time Not Working

Hi, I am working on my project but for some reason my order_by('time', 'asc') is not sorting out my list correct

As you can see number 4 and 8 should be closer together but is not I am not sure if its because the way I have my database column set up if it is please let me know what it should be.

How can I make sure is displayed by correct time or career?

PHP Code:

public function list() {
        $data['greyhounds'] = array();

        $this->db->where('track', $this->uri->segment(3));
        $this->db->where('race_number', $this->uri->segment(4));
        $this->db->order_by('time', 'desc');
        $query = $this->db->get('greyhounds');

        foreach ($query->result_array() as $result) {
            $data['greyhounds'][] = array(
                'track' => $result['track'],
                'race_number' => $result['race_number'],
                'trap' => $result['trap'],
                'time' => $result['time'],
                'form' => $result['form'],
                'price' => $result['price'],
                'career' => $result['career']
            );
        }

        $this->load->view('header');
        $this->load->view('list', $data);
        $this->load->view('footer');  
} 


Here is a copy of my database