@jonty
So wait ... I think the most interesting fact is actually this:

> This cylinder only contained 82.57/138 = 60% of the shredded
banknote pieces that the label had claimed. Although this issue
is not the focus of this paper, it appears that the Hong Kong
Monetary Authority has broken the law

In other words: Someone stole some bank notes before shredding, then filled the container up with stones to make up for the lost weight?

:D