Well,
Actually we that means that 7 of them were crashed on their first flight.
On the fleet page it only shows aircrafts that already made 1 flight. But this is going to be changed to appear all the aircrafts even if they made their first flight or not.
The airplane crash is something that all of us pay more attention to it.
We cannot have a 3 aircrafts per day crash result.
Regards,