Dutch Caribbean - 5 cent (N#2935)

Can anyone tell me what year this card was released? I can't see the date and won't detroy the card to find out. 

There doesn't appear to be a date.

The front of the pamphlet talks about the square coin rolling.

The back of the pamphlet talks about a Carribean treasure hunt.

You can't see the date on the coin?

The date on the earlier coins is split with half on the left like 19 and half on the right side like 57.

The date on later coins is in the lower point like 1984.

You could always contact the airline who issued it to find out when the treasure hunt was.

DSC07625, like you said, on older coins (before 1971) the date is split. On more recent coins (1971-1985) the date is on the obverse, which is not visible.
Meanwhile, I send a mail to KLM. As soon as I have an answer, I'll post it here.