Statement:
The level of criminal activities is lower in Sri Lanka than in Papua New Guinea

In the The Most Criminal Countries rating Sri Lanka holds position #86 2022 out of 139 and Papua New Guinea is #2 out of 139 2022.
Position of Sri Lanka is better than position of Papua New Guinea.
Papua New Guinea is leader of the "The Most Criminal Countries" rating. So it is wise to avoid visiting the country or, at least, you need to take additional actions to protect your life and belongings, compared to Sri Lanka

Referencies:

  1. The Most Criminal Countries 2022 by Numbeo
    The countries in the rating sorted by 'Crime Index' in descending order.
    Papua New Guinea 'Crime Index' value is 80.26
    Sri Lanka 'Crime Index' value is 40.97