As the PTE requirement depends upon the purpose of taking the exam, there is no average PTE score as such.

The overall score in PTE Academic is a combination of the scores achieved in all the 4 individual skills, and not the average of the scores.

As per the Common European Framework of Reference for Languages (CEF), the PTE score ranges as per proficiency levels are:

CEF Level Proficiency Level  PTE Academic score range 
A2  Basic User  24 to 42
B1  Independent User  36 to 58
B2 Independent User  51 to 75
C1 Proficient User  67 to 84
C2  Proficient User 80+

The CEF is used as a benchmark for reference to understand scores in any language qualification exam.