For roleplayers:

1st year:0-100 posts
2nd year: 100-200 posts
3rd year: 200-400 posts
4th year: 400-600 posts
5th year: 600-800 posts
6th year: 800-1000 posts
7th year: 1000-1200 posts


For non roleplayers:

1st year: 0-100 posts
2nd year: 100-200 posts
3rd year: 200-300 posts
4th year: 300-400 posts
5th year: 400-500 posts
6th year: 500-700 posts
7th year: 700-900 posts


Fifth years can become prefects.
Seventh years can become head boy/girl.


Why I made the requirements like this: roleplayers generally make more posts than non roleplayers, so I think its a bit more fair this way.