quarterly activities report, page-16

This all sounds very nice but can someone with some knowledge explain the following paragraph to me please?

"The revised resource estimation see - Table 2 - has increased overall resource tonnes by 60% and the total copper metal content by 30%. Total zinc content of the resource remains unchanged."

The little bit that wasn't in bold in says "Total zinc content of the resource remains unchanged."

What does this mean exactly?
Do we have more zinc because the amount of dirt has increased by 60% therefore at an unchanged percentage of zinc it means we have more zinc?

OR does it mean we have more dirt but no more zinc....just more dirt to get through to get the same amount of zinc previously notified?

Yes. I am a little confused by the statement. :-)

Regards
GazzaT