That's how "rates" work.

In a population of 100 the effects of 1 person doing something are far more statistically significant than 1 person doing something in a population of 1,000. A "rate" of 1 vs .1 of X event for every 100 people.

This also means that significant one-time events have more of an impact on rates in a small population than they do a larger one. Such as the mass shooting at the camp in Norway.

The rates are higher. The numbers are not. From my first example, let's say 2 out of 100 do X while 15 out of 1,000 do X. That rate would be 2 and 1.5, respectively, per 100. Higher rate for the first population but 7.5 times the number in the second population.

Rates aren't the absolute best metric, especially when extreme outlier events are included, but there's nothing factually incorrect about that graphic, as far as I know.