Expand the problem completely, and then the first unit. Overproduction percentage = actual over-production percentage compared with planned over-production, and the plan is unit one.

Increase production by 20% this year = increase production by 20% this year compared with last year. This is the first unit.

The frozen volume of water increases by 10%, and the ice behind it is one unit.

The formation of ice reduced the volume of water by a few percent. In the back, that is, water is the first unit.

In a word, it's the same sentence, fully expand the problem, followed by the first unit.