Perhaps you should try some spelling variations:
"improving port performance metrics." » "improving port performance measures.", "improving export performance metrics.", "improving court performance metrics.", "improving plant performance metrics.", "improving post performance metrics.", "improving poor performance metrics."
"improving macro performance _." » "improving crop performance _.", "improving ceo performance _.", "improving machine performance _.", "improving air performance _.", "improving care performance _.", "improving co performance _."

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("improving macro performance _.") OR ("improving port performance metrics."))~.
• Removing quotes may allow a broader search: (( improving macro performance _. ) or ( improving port performance metrics. ))~.
• Adding a wildcard symbol may retrieve word variants: (("improving macro performance _.") or ("improving port performance metrics."))*.