Percent and percentage points: two ways a share can change
When a share changes, the difference between the two percentages is measured in percentage points. If a share goes from 10 % to 12 %, it rises by 2 percentage points, which is a relative increase of 20 %. Anthrotempo gives changes in shares in percentage points.
Two different questions
Take a share that rises from 10 % to 12 %. Two statements are both true:
- It rose by 2 percentage points: 12 minus 10.
- It rose by 20 percent: the 2 points are a fifth of the starting 10.
The first answers “how much did the share change?”, the second “how much did it grow relative to where it started?”. Mixing them up makes changes look much larger or much smaller than they are.
How the site reports changes
- A change in a share or a rate given in per cent, such as the share of people aged 65 and over, is given in percentage points.
- A change in a count, such as the number of people or births, is given as a number and, where the starting value is not zero, as a relative change in per cent.
- A relative change is never computed from a starting value of zero, because it would be infinite or meaningless.
An example from the data
In the UN estimates, 6% of the world’s people were 65 or older on 1 January 1990. For 1 January 2026 the UN projects 11%. The difference between the two shares is a change in percentage points. The relative change is larger, because the starting share was small.
Last updated 26 October 2026