OpenCalais can't view importance value

Question

I'm using the PHP-OpenCalais library to extract data from pieces of text. A var_dump of the entity gives something like this:

Array
    (
        [IndustryTerm] => Array
            (
                [0] => Internet
                [1] => software maker
                [2] => Internet search
            )
        [Person] => Array
            (
                [0] => Steve Ballmer
                [1] => Jerry Yang
                [2] => Colin Gillis
            )
        [Company] => Array
            (
                [0] => Google Inc.
                [1] => Canaccord Adams
                [2] => Yahoo!
                [3] => Microsoft Corp.
            )
        [Currency] => Array
            (
                [0] => USD
            )
        [SocialTag] => Array
            (
                [0] => New encyclopedism
                [1] => Microsoft
                [2] => Jerry Yang
                [3] => Steve Ballmer
                [4] => Bing
                [5] => Yahoo!
                [6] => Internet search engines
                [7] => Hypertext
            )
    )

However, this is missing lots of information, for example, the socialTag elements don't have an importance value, which they should, as this is returned in the JSON response:

I think the problem in these lines of code from the opencalais.php class which I am using to parse the JSON response (these are lines 71-76):

foreach ($object as $item) {
        if (!empty($item->_typeGroup) && !empty($item->name)) {
            $this->entities[$item->_typeGroup][] = trim($item->name);
        }
    }