What are these percentages at different locations and how do I increase them?

I was exploring Just Cause 2 after the tutorial missions, and I found that doing things like blowing up the gas station in the town next to the guy's house or picking up weapon parts increased the percentage to the location.

• What is this percentage?
• How do I earn it? (i.e. What are the ways I can do this? Picking up weapon parts did, but killing the military didn't.)
• What is the bonus of doing this?

This percentage is the completion rate of the location. In order to complete the game 100%, you will need to complete each location.

Increasing your completion rate at a location is done in two ways:

• Picking up weapon, armor or vehicle parts
• Destroying military installations, such as electricity generators, missile silos, water towers and cranes. These are marked with the special red symbol of the military. Standard military vehicles(motorcycles, helicopters, airplanes, jeeps, boats) do not count towards this completion rate.

For each location completed, you are awarded with an additional bonus of infamy and cash. The size of this bonus is dependent on the size of the location completed.