public  class Sale
  {
      public int ID { get; set; }
      public DateTime 日付 { get; set; }
      public string 国名 { get; set; }
      public string 製品名 { get; set; }
      public double 金額 { get; set; }
      public bool アクティブ { get; set; }

      private static List<string> COUNTRIES = new List<string> 
      { "米国", "ドイツ", "イギリス", "日本", "イタリア", "ギリシャ" };
      private static List<string> PRODUCTS = new List<string> 
      { "ウィジェット", "ガジェット", "道具" };

      /// <summary>
      /// データを取得します。
      /// </summary>
      /// <param name="total"></param>
      /// <returns></returns>
      public static IEnumerable<Sale> GetData(int total)
      {
          var rand = new Random(0);
          var list = Enumerable.Range(0, total).Select(i =>
          {
              var country = COUNTRIES[rand.Next(0, COUNTRIES.Count - 1)];
              var product = PRODUCTS[rand.Next(0, PRODUCTS.Count - 1)];
              var date = new DateTime(2015, i % 12 + 1, 25);
              //string.Format("yyyy年-MM月-dd日", date);

              return new Sale
              {
                  ID = i + 1,
                  日付 = date,
                  国名 = country,
                  製品名 = product,
                  金額 = Math.Round(rand.NextDouble() * 10000 - 5000, 2),
                  アクティブ = (i % 4 == 0)
              };
          });
          return list;
      }

      public static List<string> GetCountries()
      {
          var countries = new List<string>();
          countries.AddRange(COUNTRIES);
          return countries;
      }

      public static List<string> GetProducts()
      {
          List<string> products = new List<string>();
          products.AddRange(PRODUCTS);
          return products;
      }
  }