2 mois : ration = 10%
3 mois : ration = 9.25%
4 mois : ration = 8.5%
5 mois : ration = 7.75%
6 mois : ration = 7%
7 mois : ration = 6.25%
8 mois : ration = 5.5%
9 mois : ration = 4.75%
10 mois : ration = 4%
11 mois : ration = 3.25%
12 mois : ration = 2.5%