Meanings of zero concern in English

He'd been ignoring Harrison and showed zero concern.

Coop brought up the rear, showing zero concern.

So people should have absolutely zero concern about their deposit. Tesla has delivered less than 60 Roadsters despite having taken over 1,200 orders.

Musk said investors should have " zero concern" Tesla would fail to reach its production target of 10,000 vehicles each week by the end of 2018.