displaying additional information in a metric extension

I am trying to extract some repository side information for a metric extension on some MQ targets. I'm using mgmt$metric_current and can select more or less what I want from the following sql

SELECT target_guid, key_value,

        value AS ROBIN

FROM   mgmt$metric_current

WHERE  target_type = 'wmq'

                 AND metric_label = 'Local Queues'

                 AND metric_column = 'PercentUsage'  

                 AND value > 0  

order by to_number(value)  desc

I have 2 columns here - key_value and ROBIN -

This returns data from all queues where we have a positive percent used (often many rows) but as I'm sorting I get the worst offender first.