Bonus Mission 1
You have to make sure you get an overall of 85% on the first Campaign.

Bonus Mission 2
You have to make sure you get an overall of 85% on the second Campaign.

Bonus Mission 3
You have to make sure you get an overall of 85% on the third Campaign.

Bonus Mission 4
You have to make sure you get an overall of 90% on the fourth Campaign.