Static Dropdown List Values

Question

Hi

  I have defined below dropdown list but i want Values should be saved as 0,1,2

static List<string> lst = new List<string>() { "Monthly", "Quarterly", "HALF YEARLY", "YEARLY" };
public Incentives_Period()
{
}

public static  List<string> InCentivesPeriod
{
    get
    {
        return lst;
    }
}

Thanks