TODAY’S DATA LENS

Five points is not five per cent

Square soft-grey, black and red Today’s Data Lens card showing an illustrative rise from 20% to 25% as both 5 percentage points and a 25% relative increase, with two accurately scaled hatched bars.

Observation

A rise from 20% to 25% is 5 percentage points. It is also a 25% relative increase: the five-point gain divided by the 20% starting value. Both are correct, but they answer different questions. Use points for the gap between percentages; use per cent for the change relative to where you began.

Same movement. Very different sentence.