Why did we use percentages to make predictions rather than actual measurements?

Percentage value is used for the predictions rather than the actual measurement this is so because the predictions can be wrong so the value is taken per 100 person or can be defined as per cent.

The actual measurements cannot be used because it is a prediction. Only the approximate value can be used so because there is no precise data.

There is no exact data which can be used to determine the predictions. So, prediction are always made in terms of per cent which means per 100.