When to use 'per persons'?

[joham]

When should we use 'per persons'? Or is it a wrong expression? Thank you in advance.


Maternal and Child Health: Global Challenges, Programs, and Policies


John Ehiri - 2009 - 582 页
The average malaria incidence rates across several parts of Africa with high
transmission are estimated at 1.4 per persons per year, 0.59 per persons per
year, and 0.11 persons per year for age groups <5 ...

 

[SoothingDave]

"Per person" is the normal expression.