Your php code need to include code to get and/or calculate whatever values you display. If you look at the file forum.php, you can find the code that calculates the values. I believe it depends on having 'userstats' in the $specialtemps array (near the top of the file). You would probably need to have something in your code to fetch it if it doesn't exist, so maybe something like:
Code:
global $vbulletin;
if (empty($vbulletin->userstats))
{
$vbulletin->datastore->fetch(array('userstats'));
}
// continue with code that uses userstats to calculate statistics