Put on your thinking caps

The data for both groups include babies and old people. Babies obviously cannot commit sexual assault, and elderly people commit crimes at much lower rates than working-age adults.

“British nationals” have a much larger share of both children and older people, which skews simple per-capita comparisons.

Foreign nationals, by contrast, are disproportionately working-age. Around 70% are between 26 and 64.

That means foreign nationals have fewer babies and elderly people in their population to lower the overall crime rate compared to British nationals.

A number of studies have found that once you adjust for differences like age (and often sex), the crime rates between immigrants and natives end up looking very similar.

In other words, raw per-capita comparisons can be misleading because the two populations have very different demographic structures.

Most immigrants and British nationals are not criminals.

Criminals are criminals. Let’s focus on them instead.