This is the 6947th most frequent Swedish word.
pers
"Pers" is Swedish slang for "personal record" or "personal best."
In this sentence, 'pers' is a colloquial short form for 'personligt rekord' which means 'personal record'. It is often used in sports contexts to indicate one's best performance in a specific discipline.
Jag satte ett nytt pers på 100 meter löpning.
I set a new personal best in the 100 meters running.
Here, 'pers' is a casual abbreviation for 'personer', meaning 'people' or 'persons'. It is used informally to refer to the number of people.
Vi behöver tre pers till festen imorgon.
We need three people for the party tomorrow.
In this usage, 'Pers' indicates possession and refers to 'Per', a common Swedish male name, showing that the car belongs to him. The usage indicates genitive form by adding 's'.