This has worked in teh Past

First Year - Two O's needed for Second Year

Seconds Year - Three O's Needed For Third Year

Third Years - Four O's Needed For Fourth Year

Fourth Years - Five O's for Fifth Year

Fifth Years - Five O's needed for Sixth Year

Sixth Years - Six O's needed for Seventh Year

Seventh Years - Must Pass O.W.L.S & N.E.W.T.S & Be Approved to Graduate