Get PPPoE upload and download speeds with PHP API

In the PPP page in our Mikrotik we have these tabs… Interface / PPPoE Servers / Secrets / Profiles / Active Connections

I have a working PHP code that pulls all the data from the Active Connections using this code…

require(‘inc/routeros_api.class.php’);
$API = new routerosapi();
if ($API->connect(‘$ip’, ‘$username’, ‘$password’))
{
$mik = $API->comm(‘/ppp/active/getall’);
$API->disconnect();
}

Now I want to pull the upload and download speed for each PPPoE connection from the Interface tab. I have been trying different commands for the last couple of days but have been unable to get it to work. I thought it would be something like…

$mik = $API->comm(‘/ppp/interface/getall’);

Any ideas?