Aetna Inc has a project with initial investment requiring $-160,000 and the following cash flows will be generated for the following 5 years at the end of each year because of the project: 

$40,000;

$206,000;

$134,000; 

$134,000; 

$140,000 respectively. 

If the required rate of return is 0.12, find the payback period (PB) of the project.