public int getMaxMaand(int jaar)
  {
    int maand = 1;

    // Itereer de datasets
    for (DataSet set: this.datasets)
    {
      for (Category cat: set.categories)
      {
        for (SubCategory scat: cat.subcategories)
        {
          SubCategory subcat = new SubCategory(scat.id, scat.naam, scat.datatype, scat.weight, scat.red, scat.green, scat.blue, false);

          for (Period per: scat.periods)
          {
            if (per.year == jaar)
            {
              if (per.month > maand)
              {
                maand = per.month;
              }
            }
          }
        }
      }
    }

    return maand;
  }