Didnt get the mean of a pera under DURATION for extention

Kindly make me understand this term,

Duration

Your residence permit can be extended if you meet a minimum income requirement: If, in the course of the past 12 months before submitting your application for an extension, you have earned the average salary (of the public and private sector) for new graduates with a Bachelor's degree. In 2015, the required amount is DKK 319,725.


What is this DKK 319,725? Do we need to earn that in last 12 months before extention or its total amount for 3 years or five years.. Didnt get what it means?

You need to earn per year not three year